CALOTYPE
Paper is coated with silver nitrate and potassium iodide, forming silver iodide. Prior to
use the coated paper is recoated with a solution of gallic acid, silver nitrate and acetic
acid. The gallinonitrate greatly increases sensitivity. When dry it is exposed to
ultaviolet light. It is developed with more of the gallinonitrate of silver solution. The
image is fixed with a weak hypo solution.
HAZARDS
Sodium thiosulphate (hypo) will release highly toxic sulfer dioxide gas if heated or if
acid is added.
PRECAUTIONS
Do not add acid or heat sodium thiosulphate
ALBUMEN PRINT
Paper is coated with a thin layer of albumen and sodium or ammonium chloride, and
then floated on a silver nitrate solution. When exposed to ultraviolet light the image
prints out without need for development. To obtain a better color, and to preserve the
image, the print is usually toned with gold chloride.
Hazards
The salting solution contains glacial acetic acid, which is highly corrosive to skin,
eyes and mucous membranes, and can cause respiratory problems from repeated
inhalation of vapours
Silver nitrate is moderately corrosive, eye contact can result in blindness.
Precautions for Albumen Printing
Wear gloves and goggles when handling concentrated acids.
Avoid skin and eye exposure and wear goggles when handling silver nitrate. Do not
inhale the dusts.
21 Easy Steps To Albumen Printing
by Mike Robinson
Preparing the Albumen
Get some eggs. To Make 500 mL of albumen which is enough to double coat about
50, 9 X 12 inch sheets of paper you need approximately 15 extra large eggs (if you're
clumsy get two dozen).
Separate the eggs. Start with a small dish. Be careful not to let any stringy bits get into
the egg white. If any yoke gets into the dish, don't use it. Pick out the debris and pour
the egg white into a larger container. When you have 500 mL of egg white stop.
Add to the egg, white 2 mL of 28% acetic acid, 15 mL of distilled water, and 15 g
Ammonium Chloride.
Stir, Stir, Stir, Stir until the albumen has been converted to a froth. Use a bundle of
quill pens to be authentic. One hour of stirring with an electric mixer is ok if your
can't find the pens.
Let the albumen mixture settle, covered in a refrigerator for 24 hours. Then remove
the froth that has collected on top. Filter the albumen through cheesecloth and let it
age at least a week. The older it gets the better.
Coating the Paper
Get some paper. Clear Print Drafting Vellum or Strathmore Artist Drawing - Plate
Finish are good choices for coating. The vellum is easier to handle when coating but
the Strathmore is sized better. I suggest you practice coating with the vellum and
switch to the better paper when you get the hang of it. Double coating yields glossier
prints with more even coating and greater density but it is more difficult to do.
Pour the albumen through a filter into a glass baking dish, (Pyrex 10.5 X 15 X 2
inches). Float the paper on the albumen surface. Don't get any albumen on the back of
the paper, it will print uneven density in that area.
Check for air bubbles (break them with a glass rod or plastic toothpick).
If all bubbles are gone, start the timer and float the paper for three minutes. With a
smooth and steady motion pick the paper up out of the tray starting from one corner.
Hang it up along the long side. Blot off the excess as it dries to avoid a thick edge.
(For Double coated papers only) Immerse the paper in 70% isopropyl alcohol with 3
% ammonium chloride added for about 15 seconds. This hardens the albumen for the
second coat. If you don't do this, don't bother double coating because the albumen will
wash off in the second floating.
Refloat the paper a second time. Hang it up from the opposite two corners this time
for even results. Blot off the excess along the bottom edge. Its better to sensitize as
soon as its dry, however the albumenized paper will keep well if you sensitize later.
Sensitizing the Paper
Safe light tungsten. It's nice to be able to work with the lights on! Avoid fluorescent
light. Mix 37.5 g of silver nitrate with 250 mL distilled water. This makes a 15%
solution. Silver nitrate solution is not light sensitive until it comes in contact with
organic material, such as salted albumen or human skin. Wear surgical gloves and eye
protection! Silver Nitrate splashed in eyes will cause permanent damage!
Pour the sensitizer into a glass tray. Float the albumenized paper on the solution for
three minutes after checking for air bubbles. Slowly peel the paper off the surface and
hang to dry.
Printing
Print as soon as the paper is dry. You can expect to loose about 2 stops maximum
density and speed if you wait until the next day. If you wait longer than that you'll
have to resort to citric acid preservatives and ammonia fuming to restore speed and
contrast. I doubt it's worth the effort.
Find some sunshine on a warm day if you can. A high UV light source is needed if
you print indoors. Put a suitable negative of about 2.20 density range in contact with
the paper. Use a hinged back frame so you can check exposure without disturbing
registration. Print until the shadows are just staring to "bronze". This means you've
reached maximum density. If the negative is thin, print until the highlights are about 1
to 1.5 stops too dark. The print lightens up during processing.
Processing
Wash the print to remove excess silver nitrate. The wash water turns milky when it
reacts to the silver. After about 10 minutes the wash water should be clear.
Toning. This is expensive. Untoned prints are reddish in colour. Gold toned prints
have a pleasing purple brown colour. There are many formulas available. I've tried
Borax and sodium thiocyanate formulas and prefer the Borax toner. It tones faster and
used less gold. Mix 40 mL of Berg Gold Protective Toner (Part A only) with 250 mL
of distilled water to make a solution. Add 2.5 g of Borax and stir until dissolved. Tone
by inspection. (approximately 6 minutes) Overtoned prints will be a slate gray in
colour .
Rinse
Fix. Add 200g Sodium Thiosulphate (anhydrous) to 1L of distilled water to make a
simple fixing bath.
Hypo Clear for three minutes.
Wash for at least 1/2 hour.
Squeegee dry and hang up or blot dry under weight. Albumen paper is very curly and
should be mounted according to conservator's procedures. You can store the print in
mylar sleeves with a mat board of the same size for support.
Admire
Acknowlegements:
The main source for this information has been
The Albumen and Salted Paper Book:
The History and Practice of Photographic Printing
James M. Reilly
Light Impressions
Rochester, NY 1980.
ISBN 0-87992-014-9 paperbound
ISBN 0-87992-020-3 cloth binding
Other Sources:
Care and Identification of 19th Century Photographic Prints
James M. Reilly
Eastman Kodak Company
Rochester, NY
Kodak Publication No. G-2S
CAT No 160 7787
ISBN 0-87985-365-4
Fundamentals of Photograph Conservation: A Study Guide
K. B. Hendriks, B. Thurgood, J. Iraci, B. Lesser, G. Hill
Lugus Productions Ltd.
Toronto, ON
ISBN 0-921633-80-7
CYANOTYPE
The cyanotype relies on the reaction of ferric or iron salts to light, where they are
reduced to the ferrous state. The ferrous salt reacts with the potassium ferricyanide to
from insoluble ferric ferrocyanide, also known as Prussian Blue. Separate solutions of
ferric ammonium citrate and potassium ferricyanide are made. Just prior to exposure
equal parts of the solutions are combined and the paper is coated. Once dry the paper
is exposed to UV light. The image is developed and fixed by rinsing the paper in
warm running water for about 10 minutes. The image will gradually darken as the
cyanotype completely oxidizes. The print can be oxidized by placing in a solution of
3% hydrogen peroxide. Other colors are possible by toning with a number of
solutions.
HAZARDS
Ammonium citrate and pottasium ferricyanide are only slightly hazardous. Pottasium
ferricyanide if exposed to intense heat, hot acid, or strong ultraviolet light may
decompose and release highly poisonous hydrogen cyanide gas.
Precautions for cyanotype
Do not add heat or acid to pottasium ferricyande and keep away from sources of
strong ultraviolet light.
Never mix ammonia and bleach which form lethal gases.
Wear gloves and goggles when handling ammonia solutions, and use good
ventilation.
If ferric ammonium citrate is used frequently, avoid skin contact.
A source for ready-made cyanotype paper is:
SOLARGRAPHICS
P.O. Box 7091P
Berkeley, California 94707
USA
(415) 525-1776
The New Cyanotype Process
Introduction
The cyanotype process is 153 years old. Can there really be anything new to say about
it? You probably know something of its history: invented by Sir John Herschel in
1842, (1) cyanotype was the first successful non-silver photographic printing process.
It was used for the first photographically illustrated book, (2) and later became
popular with some pictorialists, for whom a commercial paper, called ferro-prussiate,
was marketed. (3) Being simple, cheap and farily permanent, it also enjoyed an
extended period of commercial success as the blueprint process for copying drawingoffice plans, until it was made obsolete by the invention of dry, plain paper
photocopying. The word 'blueprint' still persists in our language, however, with an
expanded meaning.
What of the cyanotype process today? It's certainly useful as an inexpensive, easy
introduction to hand-coated alternative printing; in my experience, workshop
participants feel a good deal more comfortable at the outset, knowing that the
sensitizer they are wasting so freely does not cost an arm and a leg. When they've got
it under control, they can proceed to platinotype at 20p per drop!
If the growing number of cyanotypes now to be seen on gallery walls and in published
commercial work (4) is anything to go by, the process is also providing a significant
number of contemporary photographic artists with an expressive medium in its own
right, in spite of (or maybe because of) its rather strident colour. The ability to coat
this inexpensive sensitizer onto surfaces other than paper, such as wood or textiles,
gives it added versatility.
Now, after 150 years of use, you might think that there couldn't possibly be any scope
for improving the process; the textbooks (5) commonly recommend essentially the
same recipe for pictorial purposes - one that has remained unchanged since the day
that Herschel devised it by mixing strong solutions of ammonium iron(III) citrate and
potassium ferricyanide. Only the favoured concentrations vary a bit from practitioner
to practitioner. There are many up-to-date, accessible accounts of the traditional
method, for instance by Hope Kingsley (6) and Terry King (7), so I won't repeat their
work here. What I hope to show in this article is that the process can even now be
improved and made more user-friendly, at the cost of rather more chemical
manipulation in preparing the sensitizer. But first, let's examine some of the properties
of the image substance itself.
The Nature of Prussian Blue
Prussian Blue was first made accidentally in 1704, from ox blood or other animal bits,
by near-alchemical procedures (8) that defy my analytical powers. (Vegetarian
photographers may be reassured that it is now made quite inorganically.) Although
the substance has been studied for over 250 years, chemists have only recently
achieved a full understanding of its complex and varied nature. Misconceptions in
some older chemistry texts are still being perpetuated in the alternative photographic
literature.
Here beginneth the chemistry lesson. Prussian Blue is essentially ferric ferrocyanide,
[or Iron(III) Hexacyanoferrate(II) in modern chemspeak] but there exists a whole
range of such iron blues, having compositions depending on their precise method of
preparation. (9) At the molecular level, they all have in common a characteristic cubic
structure, but this lattice can accommodate variable amounts of water and metal ions
within it, so formulae range from KFe[Fe(CN)6].5H2O (the so-called "soluble"
Prussian Blue) to Fe4[Fe(CN)6]3 .15H2O ("insoluble" Prussian Blue). (10) In fact, all
forms of Prussian Blue are highly insoluble in water; the "solubility" in the former
case is an illusion caused by its easy dispersion as tiny (colloidal) particles which
form a blue suspension in water, which looks like a true solution. Chemists call this
process peptization, and it is responsible for some of the problems that beset the
cyanotype process.
By the way, the ability of the Prussian Blue lattice to act as host for relatively large
amounts of impurity ions has recently been put to good use by 'locking up' the
radioactivity that was deposited on the uplands of North Wales and Cumbria
following the Chernobyl disaster. (11) Spreading Prussian Blue on the contaminated
soil inhibited the uptake of Caesium 137 by grass; our lamb chops were thus
safeguarded from radioactive contamination, but at the price, perhaps, of turning the
green hills of Britain to navy blue! Here endeth the whimsical digression.
Although the Prussian Blue pigment of commerce can be made in a form fairly
resistant to peptization and destruction by alkalies, (12) the variety produced by the
cyanotype process is unfortunately -and inevitably- the "soluble" form. It is therefore
rather easily washed out of the paper and 'bleached' by strong alkali, which converts it
to very weakly coloured salts of iron.
Disadvantages of the Traditional Process
As an occasional user of cyanotype, I found that the traditional method seemed to
suffer from some irksome features - or was it just my incompetence? If, gentle reader,
you have already tried the process, see if you agree with me that:Printing can be rather slow compared with other iron-based processes such as the
palladiotype; exposures of thirty minutes or more to a typical UV light source are not
unusual.
The two ingredients have to be stored separately, and the solution of Ammonium
Iron(III) Citrate provides an excellent nutrient for mould growth, so that after a month
or two, it can come to resemble one of Prof. Quatermass's more bizarre experiments
(13).
The sensitizer is often not well-absorbed by the paper and some tends to lie on the
surface; being hygroscopic, it causes a tackiness which can wreck your negative.
It is disappointing to watch your picture gurgling down the sink as large amounts of
the image substance, "soluble" Prussian Blue, wash out during the wet processing.
Heavy overexposure is usually recommended as the only remedy for this drastic
weakening of the image.
Stained highlights are quite common, due to inadequate clearing and 'bleeding' of the
Prussian Blue; they may be difficult to wash out without losing gradation in the high
values.
If you agree with me about most of these disadvantages, then there is some point in
your reading on.
A Chemical Solution
The first three disadvantages could be overcome by using Ammonium Iron(III)
Oxalate instead of the citrate, because
It is more light sensitive.
It is not attacked by mould.
Its solution penetrates the paper fibres more readily (see my article on Paper).
But Ammonium Iron(III) Oxalate also causes a chemical problem, because when it is
mixed with Potassium Ferricyanide to prepare the sensitizer solution, the sparingly
soluble salt, Potassium Iron(III) Oxalate, crystallises out. A 'gritty' sensitizer is
useless, and if this happens within the sensitized paper it can cause quite pretty, but
totally unwanted fern-like patterns. The answer to the problem would be to use
Ammonium Ferricyanide instead of the Potassium salt, but this is unobtainable (so far
as I know) and rather troublesome to make.
Disadvantages (4) and (5) are due to the fact, already stated, that the cyanotype
process produces the so-called "soluble" form of Prussian Blue. Substitution of
ammonium ions for potassium ions in the structure would have the benefit of
diminishing this tendency, yielding an "ammonium blue" of good colour, which is
more resistant to peptization and alkalies.
All these problems (1) to (5) can therefore be overcome by the simple trick of
eliminating most of the potassium ions from the sensitizer; this is achieved by adding
finely ground solid Potassium Ferricyanide to an appropriate excess of a very
concentrated solution of Ammonium Iron(III) Oxalate, allowing it to crystallise then
filtering off and rejecting the solid Potassium Iron(III) Oxalate that results. The
biggest objection to this procedure is the present artificially high cost of Ammonium
Iron(III) Oxalate, but cheaper sources of this chemical are now becoming available.
The 'user friendly' sensitizer is a single solution with a very good shelf life, and it
provides excellent image quality.
The following recipe is not engraved on tablets of stone; it has given the author very
satisfactory results so far, but deserves to be more extensively tested, and may yet
allow room for improvement by fine-tuning the concentrations.
Sensitizer Chemicals needed
Ammonium Iron(III) Oxalate (NH4)3[Fe(C2O4)3].3H2O .....30 g
Potassium Ferricyanide K3[Fe(CN)6] ......................................10 g
Ammonium Dichromate (NH4)2Cr2O7 (25% solution) .........0.5 cc
Distilled water to make ............................................................100 cc
GPR Grade (98-99%) purity is adequate.
Preparation of Sensitizer
The preparation of this sensitizer solution calls for a bit more experience in chemical
manipulation than is required to make a traditional cyanotype sensitizer, so don't
undertake it unless you are fairly confident. This work should be carried out under
tungsten light, not fluorescent or daylight.
Please note that all the chemicals are poisonous!
Using a pestle and mortar, finely powder 10 g Potassium Ferricyanide. Wear a dust
mask, to avoid inhalation of the powder, and pay attention to thoroughly completing
this step, which is indicated when all the red crystals are crushed to a yellow powder.
Heat ca. 30 cc distilled water to ca. 50 °C and dissolve in it 30 g Ammonium Iron(III)
Oxalate.
Add 0.5 cc 25% Ammonium Dichromate solution, (previously prepared by dissolving
5 g of the solid in distilled water and making up to a final volume of 20 cc). Mix
thoroughly.
To the solution, while it is still hot, add the 10 g of finely powdered Potassium
Ferricyanide in small portions with vigorous stirring; few (or preferably no) red
crystals should be seen, and green crystals will begin to appear. Set the solution aside
in a dark place to cool and crystallise for about one hour.
Separate most of the liquid from the green crystals by filtration. The green solid
(Potassium Iron(III) Oxalate) is disposed of safely (poisonous!). The volume of
solution extracted should be ca. 30 to 33 cc.
Make up the olive-yellow coloured solution with distilled water to a final volume of
100 cc. The sensitizer can be made more dilute (e.g. up to 200 cc): it will be faster to
print, but yield a less intense blue.
Filter the sensitizer solution and store it in a brown bottle kept in the dark; its shelf
life should be at least a year.
Use of Wetting Agent
With some papers the use of a wetting agent can greatly improve the ease of coating
and the retention of Prussian Blue by the paper fibres. I prefer Tween 20
(polyoxyethylene sorbitan monolaurate - a non-ionic surfactant) which may be added
to the sensitizer solution to produce a final concentration of ca. 0.1 to 0.5%. A stock
solution of concentration 2% is useful for this: if you find it necessary, add one or two
drops per cc of sensitizer and mix well just before coating. The appropriate amount
will depend upon the paper, so it is better not to add it to the bulk of the stock
sensitizer solution unless you're certain what paper is to be used: Tween 20 is very
suitable for Silversafe and Buxton papers, but may interact unfavourably with gelatinsized papers.
Choice of Papers
The cyanotype sensitizer is a delicate test of paper quality - especially if the coated
paper is left for some hours in the dark at normal relative humidity: any change of the
bright yellow coating towards a green or, worse, blue colour is an indication of
impurities or additives in the paper that are hostile to this process (and possibly to
other processes as well). I recommend Atlantis Silversafe Photostore 200 gsm, Arches
Platine 310 gsm, and Whatman Watercolour 290 gsm; but the best results (of course!)
are obtained on Ruscombe Mill's handmade 'Buxton' paper, (see my article on paper).
Coating Techniques
Coating by the rod method will require approximately 1.5 cc of sensitizer for a
10"x8"; brush coating consumes more, but try to avoid excess sensitizer which may
puddle and crystallise. I have to remind you that this sensitizer solution is toxic if
ingested (much more so than traditional cyanotype) and it will obviously stain skin,
wood, clothes, textiles, household pets and any other absorbent surfaces.
Drying
It is simplest to let the sensitized paper dry at room temperature in the dark for about
one hour; but there will be no difference if you prefer heat-drying at about 40°C for
10 minutes. Expose the sensitized paper within a few hours of coating, if possible. Its
storage life depends on the purity of the paper base, as mentioned above; it will keep
longer in a desiccated enclosure. The coated side should remain light yellow: if it has
turned green or blue reject it, because the highlights will be chemically fogged, and
look for a better paper.
Negatives
For a full tonal range in the print, the negative should have a long density range of at
least 1.8, like those for platinum-palladium printing; i.e. extending from base+fog at
around 0.2 to a Dmax of 2 or more. This is achieved by "overdeveloping" the negative
to the extent of 70%-80%.
The contrast of the sensitizer can be lessened by adding citric acid, so that it can even
accommodate a negative density range of 2.6 or so. Conversely, the contrast can be
increased by the addition of more ammonium dichromate solution.
Unlike the traditional cyanotype sensitizer, I have not encountered any problems with
this sensitizer damaging negatives during contact printing.
Exposure
Whether the light source is the sun or a UV lamp, exposure is much shorter than that
needed for the traditional Cyanotype recipes - this new sensitizer requires about five
minutes exposure under an average light source.
Since this is a print-out process, a traditional hinged-back contact printing frame
should be used; the image can then be inspected without losing registration and the
correct exposure reached without the need for preliminary test strips. The exposure is
continued until the high values just appear green, the mid-tones are blue, and the
shadow tones are substantially reversed to a pale grey-blue, giving the image a
"solarised" look.
If you do not mask your negative when printing (with ruby lith tape, for instance) but
expose the entire coated area, then you will never know if the print is properly
cleared. This is the disadvantage of 'showing the brushmarks' to prove it's a handmade
print.
Wet Processing
You can process the exposed paper most simply with nothing more than a few
changes of water, but a better gradation with stronger shadow tones is obtained if it is
treated initially in a bath of citric acid solution (strength1% to 2%) for 10 minutes.
This bath should be replaced after a few prints have passed through it: typically, 1
litre will process ten 10"x8" prints. The yellow stain of sensitizer should clear
completely from unexposed areas - it is worth holding the print up to a bluish light to
check that no yellow stain remains in the interior of the paper; if the stain persists, use
a second citric acid bath. Finally wash gently in running water for about 20 minutes.
Unlike prints made by the traditional recipe, there should be very little loss of image
substance during this procedure.
The reversed shadow tones usually regain their full values quite rapidly during the
wet processing, but if not they will do so during drying (24 hours). However, if you're
anxious to see the final result immediately, then immerse the print in a bath of 0.3%
hydrogen peroxide (50 cc of the 6% solution -so-called "20 volume"- diluted to 1 litre
of water) for no more than half a minute. This treatment makes no difference to the
final result.
Disclaimer
It is the responsibility of the user of toxic chemicals to take appropriate precautions to
avoid ingestion. The author cannot accept liability for any injury, sickness or damage
resulting from this process.
KALLITYPE
The kallitype is an iron-sensitive process that uses silver to form the image. The
kallitype emulsion is a mixture of ferric oxalate and silver nitrate, with the addition of
either oxalic acid or potassium oxalate. When exposed to light the ferric oxalate is
changed to the ferrous state, which reduces the silver nitrate to the metallic silver.
When developed the ferrous oxalate is dissolved and the metallic silver is left forming
the image.
The kallitype process is a very unforgiving one, great care must be taken. The
resulting prints are quite similar to platinum prints, however kallitype prints are not
nearly as permanent as platinum, although substantially cheaper to produce.
Hazards
Silver nitrate is corrosive to the skin , eyes and mucous membranes, eye contact can
cause blindness. Oxalic acid and ferric oxalate are highly corrosive. Gold chloride
used for toning is a moderately irritating compound that can cause severe skin and
respiratory allergies. The developer may contain potassium dichromate increasing
skin and respiratory hazards, causing skin and respiratory allergies and ulceration.
Potassium dichromate is a suspected human carcinogen. The fixer contains ammonia
which is highly irritating to the eyes and respiratory system.
Precautions for Kallitype Printing
Wear gloves when handling silver nitrate. Do not spray on silver nitrate sensitizer
unless done in a spray booth
Wear gloves and goggles when handling ferric oxalate or oxalic acid solutions. Mix
solutions in a fume hood or inside a glove box, or wear an approved toxic dust mask.
Wear gloves whenhandling potassium dichromate or pottasium oxalate. Mix solutions
in a fume hood or inside a glove box, or wear an approved toxic dust mask.
Kallitypes
Photography improves in a constant way, forever in the same direction. Films are
faster, lenses more luminous, shutters are working at 1/4000 s. Images of our world
that condescend to stay in our mind are such tiny moments, joined end to end, they
rarely excess a few minutes. The waves of images are invading our daily world
without giving us the time to really see them. Television, video, newspapers,
magazines, publicity and posters bring everyday a stupefying harvest of what some
still dare to call "choc des images" (image impact).
As a reaction to this tendency of photography, I wanted very much to find a way to
depart, travel, photograph and send very personal and emotional images to some
friends. I wanted this photography to be quite elementary (rudimentary) and
concentrated. By concentrated, I mean that the concentration of the photographer,
between the exposure and the final result, should not relax. A complete cycle of image
creation would have to happen at the same place without discontinuity. The
photographic image would then be able to become impregnated with the location and
the confrontation of the photographer with his subject would last more than 1/125 of a
second. The pinhole camera is the only solution because of its exposure time of many
minutes.
All alone on my island with the pinhole camera, two hours rowing hard from the
civilisation, I was happy. I was thinking of the pioneers, Charles Nègre and others,
who much sooner than me, had enjoyed developing on location. Yes, processing on
site, that was important. Polaroid film, the only concession to modernism gave me the
possibility to do it. Have you ever tried to wash your negatives with seawater, you
should try it!
A small amount of watercolour paper, impregnated with kallitype emulsion, was my
printing paper, which was contact-exposed in broad daylight. The richness of tone of
the kallitype (sometimes enhanced with metallic brilliance due to silver excess), the
versatility of the process, and the free choice of the paper all persuaded me
THE PLATINUM AND PALLADIUM PRINT
The platinum and palladium print is considered by many to be the finest monochrome
printing process. Platinum prints are capable of producing a long rich tonal scale,
tremendous depth of shadows and the subtlest highlight details.
The platinum print is another iron sensitive process. Two sensitizing solutions and a
platinum solutions are made:
a ferric solution of oxalic acid and ferric oxalate
a ferric-chlorate solution of oxalic acid and potassium chlorate
a platinum solution of potassium chloroplatinite.
The three solutions are mixed together just prior to coating. Different concentrations
of the sensitizing solutions can be used to vary the contrast of the resulting emulsion.
The paper must be coated using a brush with no metallic surfaces (reacts with
platinum). After drying the paper is exposed to ultraviolet light. The paper is
developed in a solution of potassium oxalate. The image develops instantly so the
print must be immersed in the developer instantly. The print is then cleared in three
succesive baths of, for instance, hydrochloric acid clearing solution.
When the ferric salts are exposed to light, they reduce to the ferrous state. When the
image is developed in pottassium oxalate, the platinum reduces to to the metallic
state, where it has been exposed and in contact with the ferrous salts. The image is
first formed by the iron and then by the platinum after development. Unexposed
platinum and ferric salts are dissolved out. All traces of iron are removed by the
clearing bath, leaving an image formed entirely of platinum.
Platinum prints are one of the most permanent printing media. The major
disadvantage of platinum printing is the high cost. Palladium reacts almost exactly the
same as platinum, and the two printing media are quite similar. Palladium prints are
much warmer than platinum. The process details for palladium are almost identical,
with a few minor changes. Palladium is substantially cheaper than platinum.
There are a number of reference books on platinum and palladium printing. Please see
the Reference section at the end of this FAQ.
Hazards
Platinum salts are irritating to the eyes, skin and respiratory system. These chemicals
are capable of causing skin allergies and platinosis a severe form of asthma. The
sensitizer, developer, clearing baths and some of the toning solutions contain highly
corrosive acids and oxalates that have signifigant skin, eye, respiratory and ingestion
hazards. The oxalate developer, which is saved and reused, picks up metals from the
paper and becomes more toxic with use.
Precautions for Platinum and Palladium Printing
When handling pottasium chlorate, especially when combining it with hydochloric
acid, work in a fume food or wear an approved respirator with a gas cartridge
Store pottasium chlorate seperately and away from heat and combustable material.
Do not use glycerin for local toning, because it creates an explosion hazard when
combined with potassium chlorate
Wear gloves and goggles when handling when handling platinum or palladium salts.
Mix in a fume hood or inside a glove box, or wear an approved toxic dust mask
Wear gloves and goggles when handling when handling oxalic acid or oxalate
solutions. Mix in a fume hood or inside a glove box, or wear an approved toxic dust
mask
A palladium and gold printing out
and development system
Background
Handcoated platinum printing out papers are nothing new.
Pizzighelli describes several methods in Lietze's 1888 book "Modern
Heliographic Methods" and Mike Ware described his method in the
British Journal of Photography, Vol. 133(No 42), pp1190-1194 (17
October 1986), or 'An Investigation of Platinum and Palladium
Printing', Journal of Photographic Science, Vol. 34, pp13-25 1986.
These methods rely on a simple system of incorporating moisture in
the emulsion and paper to facilitate the developing out of the
platinum salts during exposure.
Pizzighelli's method uses sodium ferric oxalate or ammonium ferric
oxalate instead of ferric oxalate because of it's hygroscopic nature,
chemically absorbing moisture.
Ware's method improved on Pizzighelli's with the use of ammonium
chloroplatinite for the standard potassium chloroplatinite in order to
achieve higher solubility.
As Ware states "the photoproduct from ammonium ferric oxalate is
not an insoluble ferrous oxalate but a soluble oxalato complex of
iron II, hence the printing out effect".
Tests that I have performed confirm that a water is of some form is
essential for any degree of success. With the Ziatype lithium
version, the moisture comes from its hygroscopic nature. With the
cesium brown version, it is suspected that there a high percentage
of water bound into the double salt of palladium and cesium.
Humidifying a traditional ferric oxalate paper and printing it will
result in a stronger print out image, but it will not be permanent
enough to withstand water development and will typically appear
quite grainy.
The Bostick & Sullivan Ziatypei i system, like the Pizzighelli and
Ware methods makes use of hygroscopic ii chemistry and
ammonium ferric oxalate as key to its printing out capability. In the
Ziatype lithium chloropalladite and ferric ammonium oxalate are
used.
Palladium
When exploring the use of other palladium chloride compounds in
the photographic process I came across a note which stated that
lithium chloride was perhaps the most hygroscopic material known.
I then surmised that its palladium salt would also display similar
traits.
Lithium chloropalladite is a rare compound and is not listed in any
of the common chemical references. Since palladium makes double
salts with most of the alkali metal chlorides, I calculated its formula
as 1.4 gms of lithium chloride to 2.3 gms of palladium chloride.
Even though it is rare, our lab can produce it at prices competitive
with the traditional sodium palladium salt.
To be on the safe side I used 1.7 gms of lithium chloride as the
slight amount of extra lithium chloride should have no deleterious
effect while any free palladium chloride might. Lithium chloride is a
fairly benign chemical, and has been used in drugs for treating
depression. I understand that it has no narcotic effect or 'high' for
non depressives.
My first experiment making prints used the standard ferric oxalate
solution and lithium chloropalladite. I made up the emulsion, and
coated then dried the paper in the normal manner. I then steamed
the coated print over a inexpensive sickroom humidifier vaporizer.
The results were somewhat promising.
A very strong print out image was produced, but the contrast was
very high, a great deal of graininess was produced, and the image
darkened considerably when washed in the water. After several
prints I noticed that the darkening was increasing with each print.
I suspect that this was due to the small quantity of EDTA
tetrasodium that we add to our standard ferric oxalate solution.
EDTA tetrasodium has a developing effect on any platinum print. I
switched to an EDTA-free ferric oxalate solution and the darkening
went away, but the prints remained grainy and contrasty.
My next experiment was to follow Pizzighelli's recommendations and
use a 40% solution of ferric ammonium oxalate instead of ferric
oxalate. I called this solution No 1. The print out image created was
quite strong and no darkening was observed during development.
The negative I chose was a little on the flat side and needed a boost
in contrast.
I then made up a solution of ferric ammonium oxalate with some
potassium chlorate, which I labeled No 2. In the manner of
traditional platinum printing I mixed a portion of Numbers 1 and 2.
The first print I made used a 50-50 mix of solutions Nos. 1 and 2,
and the contrast was perfect for the negative I used which was a
little flat.
The prints produced were neutral black, with a dead slate gray in
the mid tones and hint of brown. They appeared very much like
pure platinum prints.
After some fine tuning, I became excited as I was producing pure
palladium prints with the beautiful gray and black tones of a
classical platinum print. Frederick Evans could have not done better!
Well at least in the color area. I don't propose that my negatives
are in the same league with his.
Warm tones with Cesium
As the Ziatype was being tested by some of our better printers, the
one thing that many wanted was the ability to produce warm toned
prints.
My first experiments were to try the traditional platinum printers
warm up chemical, mercuric chloride. Replacing part of the lithium
palladium salt with mercuric chloride does impart a slight warmth to
the image, but we have to deal with a highly poisonous chemical
and we also have the added problem of how to dispose of it safely.
After a Thomas Edison like scientific quest that found me dumping
all sorts of chemicals into the emulsion, none of which produced any
warmth in the image, and many which produced useless lumpy
precipitates, I decided to go back to the alkali double salts of
palladium. Lithium is at the top of the periodic table and is the third
lightest element next to hydrogen and helium. It's really a gas
masquerading as a metal. I figured that if a light element produced
cold tones a heavy one might produce warm tones, so I scanned
down the left side of the chart and at the bottom of the alkalis is
francium of which my Merck Index says is produced by the
bombardment of thorium with protons, is exceedingly rare and very
expensive. Scratch that! Next element up is cesium, and Merck says
that the chloride is highly deliquescent, thus a good chance the
palladium salt will be also, and not too expensive at a buck or so a
gram.
It works. Cesium chloropalladite produces a lush warm tone print
when used in the printing out Zia system. Remarkably, however, it
does it in quite a different manner than lithium chloropalladite. The
cesium palladium salt makes images while dry, no steaming is
necessary, and in fact, if steamed it will produce cold tones. The
lithium palladium salt will not produce anything other than a blotchy
blur if exposed dry.
Many people associate cesium with the atomic clock at the National
Bureau of Standards in Washington D.C.. That clock runs on a
radioactive isotope of cesium. Many normally non radioactive
elements have radioactive isotopes and cesium is one of them. The
cesium salt we use in non radioactive and in fact, the teeny tiny
portion of the hot stuff is removed before it ever gets to us.
The downside of using cesium is that at the concentrations
necessary, it must be warmed up or kept warm to keep it in
solution otherwise a chunk of undissolved salts will remain in the
bottom of the container rendering the solution too week for good
prints.
Warm tones with Tungsten
The cesium palladium process had some drawbacks" it solarized,
and it needed to be kept warm to keep it in solution, I continued my
quest for simpler system to produce brown Ziatype prints. After
some intensive experimentation. I tried sodium tungstate as an
additive. It worked! Finally an easy way to control the amount of
brown color to the Ziatype print. The color is attractive and runs
from a hint of brown to full sepia depending on how much of the
tungsten salt is added. Sodium tungstate is a relative harmless
chemical, the Merck Index says that lethal dose for guinea pigs is
990 mg/kg.
Roughly translated you would need approximately 70 grams to be
lethal in a 160 lb. man. I had judiciously avoided experiments with
mercury, due to its high toxicity and disposal problems.
I feel that the tungsten method is the method choice, however I am
going to leave the cesium formulas in this document as there are
those who may wish to experiment with it. Who knows, it may lead
to other avenues of platinum printing.
Blue and purple tones with gold
One of the most interesting aspects of the Ziatype system is that a portion or almost
all of the lithium chloropalladite can be substituted with gold chloride. My tests with
other double salts of palladium show that invariably the gold reduces out and stains
the highlights of the print. Lithium chloropalladite seems to have a unique property of
not reducing out the gold.
The color shift varies from slightly warmish prints with purplish brown overtones to
full lavender purple prints. My experiments have shown that up to 80% of lithium
chloropalladite solution can be replaced with drops of 5% gold chloride.
Replacing all of the lithium chloropalladite with gold requires a double strength ferric
ammonium oxalate and 10% gold chloride. My suspicions are that a small quantity of
palladium is needed to strengthen the effects of the gold. There is little difference in
color or contrast between a 5 x 7 print made with 7 drops of 5% gold chloride and a
print made with 8 drops of 10% gold chloride.
Perhaps it is only a semantic argument that one print could be said to be pure gold,
while the other is only 80% gold and 20% palladium.
The addition of gold, however, increases contrast considerably,
especially at higher percentages. As information is obtained from
workers in the field, we'll pass it on it future Ziatype instructions.
After exposure and before washing/ clearing, re-steaming the print
will usually intensify the image. The intensification can be observed
while the steaming takes place.
After exposure steaming deepens the blacks, and raises the
contrast of the image. Prints with higher percentage of gold show
more response to the steaming, even to the point of becoming
harsh and gritty.
I suspect that using a more subtle humidity arrangement than the
vaporizer spout might prove to give more control over this
phenomena.
With a straight palladium Ziatype, if there is some drying during
exposure, steaming will also complete any print out effect lost due
to drying.
Printing Out and Self Masking
Since the Ziatype print is developing as it exposes the print will
exhibit what is called "self masking." The first values to show are
the lower "shadow values," Since the print darkens as it exposes, it
will mask further developing out in those values. As the exposure
continues, higher values will darken and this darkening will mask
further developing out in those values as well.
In a "normal" developing out print, overexposure will push the low
values out on the toe of the curve, resulting in "crushed" shadow
values. One can think of the values on the curve as sort of a train,
pushing on one end will push the values equally down the curve. In
the Ziatype or POP one can think of the values as an accordion, as
exposure continues, the lower values more or less stay fixed and
the upper ones move down.
Traditional POP paper only came in one paper grade mostly due to
its self masking property. One grade of paper could handle a wide
range of negative contrasts. Contrast is controlled to a large degree
by exposure.
Reports from the field are indicating that any exposure less than 2
1/2 minutes in a UV fluorescent light bank is probably too short
even if the overall exposure is good there may be some crushing of
the midtone values. In this case add more No. 2. ammonium ferric
oxalate or a drop or two of a 8% potassium chlorate solution. This
will boost the contrast, which you can then reduce by increasing the
length of exposure. This technique can be used to expand the
middle values. Since the Ziatype black can take large amounts of
No. 2 or "chlorate boost" without graining up, this can be a valuable
technique, however, printing times can increase at an alarming
rate.
Developing Out
This system has another remarkable property in that it will work as
a traditional developing out system as well as a printing out system.
Standard developers such as potassium oxalate or ammonium
citrate produce light airy sepia prints. Using a Cold Bath developer
will produces a rich black-brown print, similar to a ferric oxalate and
sodium palladium print, but with a bit more warmth.
A great deal of image control can be gained by mixing the printing
out and developing out aspects of the Ziatype.
A slight humidity-steaming, which will produce some image during
exposure and then developing the print in Cold Bath or other
developer can produce tones in between cold black and sepia. If
done with skill or if a little serendipity joins you, split tones can be
produced.
I produced some interesting split tones with gold and palladium; the
shadows being brown-black, the mid-tones and highlights moving to
lavender-purple.
Pure Ziatype is highly predictable and controllable. Playing in the
area of mixed modes (POP- developing out) and split tones can be
maddening and is not for the faint of heart. Those who venture into
this area should be more a student of John Cage and less of Ansel
Adams. There can be sheer delight in producing a gorgeous split
toned print, followed by the agony of not being able to do it again.
MAKING ZIATYPE PRINTS
THE CHEMICALS
Clearing Baths
Use Either:
*
*
*
*
sodium sulfite
15 gm
water
1000 ml
citric acid
15 gm
water
1000 ml
Kodak Hypoclear
25 ml
water
1000 ml
EDTA tetra-sodium 15 gm
water
Solution No. 1
Solution No. 2
Solution No. 3
Lithium chloropalladite:
Charcoal Black
Solution No. 4
Warm tone additive:
Solution No. 5
Contrast boost - 8%:
Solution No. 6
Gold chloride:
For gray/blue/purple
tones
1000 ml
ferric ammonium
oxalate
10.0 gm
water
25.0 ml
ferric ammonium
oxalate
10.0 gm
potassium chlorate
2.0 gm
water
25.0 ml
palladium chloride
2.3 gm
lithium chloride
1.7 gm
water
25.0 ml
sodium tungstate
4.0 gm
water
25.0 ml
This solution may be diluted for smaller
prints.
1 drop of this concentration will produce
quite a bit of warmth in an 8x10 print.
potassium chlorate
2.0 gm
water
25.0 ml
gold chloride
5%
solution
Clearing and Washing
Rinse in plain tap water. It will clear in about 1 minute.
Follow with a 5 minute wash.
Some papers may show some yellow staining due to not clearing
sufficiently, if this happens use sodium sulfite or Kodak Hypoclear or
equivalent to remove the stain and then follow with a 5 minute
wash.
The Procedure
The ratio of the coating solutions is the same as in normal palladium
printing. The total drops of ammonium ferric solution will equal the
number of drops of lithium chloropalladite or cesium chloropalladite.
Vary the portion of No 1 and No 2 to obtain the contrast level
needed. Use more No 1 for lower contrast prints, more No 2 for
higher contrast prints. The Ziatype process will handle a print with
high levels of No 2 with no visible increase in graininess.
Use the lithium chloropalladite for cold tones , for warm tones add 1
or more drops of sodium tungstate Solution No. 4.
For a 5 x 7 print with a mid level of contrast, a good starting point
would be 4 drops of Solution No 1, 4 drops of Solution No 2, and 8
drops of Solution No 3. Remember that the total of Nos. 1 and 2
should equal the No 3, and the No 3 can be a mix of a, b or c.
* If more contrast is needed, use one or more drops of Solution No.
5, the 8% contrast boost. A half strength can be made and used as
well.
* I prefer to coat with a glass rod, though a brush will work. The
trick is to get enough, but not too much emulsion on your paper.
When coating a 5 x 7 print with a glass rod I've found that 3 or 4
slow swipes across the print is enough. The last swipe pulls any
excess emulsion to the edge of the print or off the paper entirely iii.
* Dry with a hairdryer or use the method you've been drying your
standard platinum palladium prints .
Hold the print over the spout with the emulsion side facing the
spout and move the print around to steam the paper evenly.
(At first I used an inexpensive Sunbeam Model 300 steam
humidifier purchased at a drugstore for $9.00. It worked but had a
tendency to spit. Other Ziatype workers have reported better
results with the electrostatic vaporizers.
The Sunbeam versions of these cost in the $40.00 range I have not
been extremely careful, and my results have been good. The
emulsion seems to readily absorb the moisture. I humidify a 5 x 7
print for about 30 seconds.)
* Quickly place the print in a print frame and place a piece of
acetate or acrylic between the frame back and the paper to retain
the print moisture. This can be any plastic sheeting and is best if
the size fits the frame fully. Also a Mylar negative sleeve can be
used, just place the coated paper in the sleeve and in this way, both
the negative can be preserved and humidity can be maintained..
* Expose the print either in the sun or with a UV light source. Within
a minute or two in the sun, or several minutes under artificial light
you will see the margins darken. In a few minutes more the
margins will darken to a dark purple black.
(You may want to use a piece of 1 mil Mylar or acetate between the
negative and the paper to prevent any damage to the negative.)
* A standard print frame is recommended as this allows you to
check the progress of the printing out. When the print appears as
full and complete, you are finished printing.
(A moist paper towel placed between the acrylic dam and the back
of the print frame helps retain moisture during exposure though it is
usually not necessary. The order: frame glass, negative, Ziatype
coated paper, plastic dam, damp paper towel, back of print frame.)
* Immerse the print in water and wash for 5 minutes. With some
papers there may be a yellow tint left in the paper. In this case
clear for 5 minutes in Kodak Hypo clear or equivalent, or sodium
sulfite, or any other platinum clearing agent, then rewash for 5
minutes.
* Blot and complete drying on a screen.
* Sell for money, give to friends, or keep in a secret box under your
bed to be privately enjoyed when you're feeling down.
Color Control
Red/blue
For a color shift to the burgundy and lavender shades, substitute
gold chloride (3c) for the lithium palladium chloride(3a). Gold
chloride can be substituted for up to 80% of the lithium chloride.
1 drop out of 8 will only give a slight burgundy shift, 7 drops out of
8 will give a bright purple print. It is difficult to substitute all of the
gold as a small quantity of lithium palladium chloride is needed to
maintain density if gold is used.
Brown tones with cesium chloropalladite
Use cesium chloropalladite (3b) instead of the lithium
chloropalladite. Do not steam after drying. It will produce a
strong print out image and will be several stops slower than the
lithium version. After exposing a dry cesium print, the print can be
steamed before placing in the water bath.
This will reduce contrast and bring up the underexposed highlights.
A print placed directly into the water bath may undergo a slight
increase in development over the printing out image. If it is desired
to prevent this increase in image density, use a first water bath of 5
grams of potassium dichromate to a liter of water. This may also
increase the contrast of the print slightly.
Important!
The cesium chloride will need to be warmed before using as at its
concentration, it will crystallize out at room temperature.
Temperature should be 90 to 120 deg. It is not critical as a few
crystals in the bottom will not hurt and if too warm, it will cool off
when mixed with the ferric ammonium oxalate anyway.
The Ziatype cesium brown will not tolerate the large amounts of No.
2 or chlorate boost and the black will. It is more prone to graining
up with large amounts of No. 2.
So far the use of gold in a print with cesium chloropalladite is
problematical in that the gold tends to reduce out and stains the
prints highlights.
Split tones
A lithium coated print that is fully steamed before exposure and the
humidity being preserved during exposure by the use of a plastic
dam between the frame back and the print will produce a neutral
black image with pure palladium. If the paper is slightly dried before
exposure, the resulting print will have a brown cast to it.
The print out image will not be as strong as a fully steamed print
but if re-steaming is done after exposure the print will darken. A
Ziatype palladium print that is dried and not steamed before
exposure will give little or no printout image. It will develop out fully
with steaming after exposure and will be sepia in color.
If Cold Bath Developer is used the print will be a rich brown-black.
Most other standard pd/pt developers will produce brown to sepia
images.
Platinum
Small quantities of the traditional potassium chloroplatinite can be
added to the Ziatype in substitution of the lithium palladium
chloride. We recommend that no more than 25% of your lithium
palladium solution be substituted with platinum.
The addition of platinum will boost midtone contrast which can get
crushed somewhat when printing long scale negatives.
Ammonium chloroplatinite can be used alone or in conjunction with
the lithium palladium chloride.
Benefits of the Ziatype System:
* Print by inspection, what you see is what you get. The print fully
develops in the light as you expose it.
* A choice of a traditional timed developing out system with the
same chemistry.
* No solarization even with pure palladium.
* The benefits of a self masking printing system.
* Color controls with palladium from charcoal black, to sepia. With
gold and palladium, from burgundy, to raging purple with no
highlight staining.
* No developer and usually no clearing agent is needed.
* Better contrast control with less graining using No. 2 than with
developing out systems.
* Better paper tolerance, it's not as picky about the paper it's on.
* Printing speeds increased by as much as two stops in many cases.
Notes:
I have been using Cranes Platinotype, Cranes Parchmont Wove, and
Cranes Kid Finish AS8111 paper with good results.
Many of these tests were performed in Santa Fe, New Mexico,
elevation 7000 feet (2200 meters). Temperature was near 80^F
(25^C) and the humidity was below 20 percent . If it works here it
should work most anywhere.
Toxicity Issues
Since both Lithium chloropalladite and cesium chloropalladite are
very rare compounds and are not in general use in industry, there is
no available toxicity data. However groups of compounds usually
share similar toxic characteristics. For instance mercury
compounds, if water soluble, are all poisonous, as are most
cyanides. The lethal dose for cesium chloride is listed as 1.5 g per
kilogram in mice and lithium chloride as 1.06 gram per kilogram in
mice.
This roughly translates into 50-75 grams for a lethal dose in a 150
lb human. The are only modestly poisonous. Palladium chloride is
18 mg (thousands of a gram) per kilogram in rabbits as a lethal
dose. We can extrapolate that the cesium and lithium versions of
the palladium salts are only very slightly more poisonous than the
sodium tetrachloropalladite in common usage in palladium printing.
Disposal
Bostick & Sullivan will be happy to recycle any leftover quantities of
platinum or palladium salts. For small quantities , dilute with several
volumes of water and soak a piece of steel wool in it overnight. The
steel wool will become plated with the platinum or palladium metal
from the solution leaving the harmless chloride behind. There
should be some dark sludge which will be harmless iron compounds.
The steel wool can be safely disposed of and the chloride should be
sewer disposable, though you should check any local ordinances,
especially if you are on a cesspool.
This method can be used to remove any platinum or palladium from
developer solutions.
Powdered zinc can also be used in place of the steel wool.
Most problems reported seem to be caused by using too much
sensitizer as mentioned in footnote 1
i Named for the ancient Southwest Anasazi symbol for the sun, familiar as the circular
image with 4 sets of 4 rays seen on the flag of New Mexico and its license plates. It
seemed appropriate as we have just moved to New Mexico and I have been using its
sun to make the prints
ii Hygroscopic: readily absorbing moisture, as from the atmosphere
iii Too much coating will cause grain and splotchiness in the print, This is due to the
printing out nature of the process. The printed out portion will mask any sensitizer
underneath the exposed layer, and if tiny particles of the top layer flake off, the
bottom layer will not be exposed and show as white grain. There is no gain in dMax
obtained by heavy coating.
Ziatype Images provided
by Dick Sullivan
The urban landscape is
called "The Cornfield".
That's the historic
name for the area
where the tracks are.
It's by Richard Sullivan
c. 1982. It's of the LA
skyline. It's a Lithium
Palladium Ziatype with
some gold.
This image is from a c.
1905 glass plate 4 x 5
negative by Harry
Smith, a Danish
American photographer
active in San Francisco
at the turn of the
century. It's called "The
Cook Tent". It's a
100% Cesium
Palladium Ziatype.
"LA Wall" by
Dick Sullivan
1989, Ziatype
Lithium
Palladium and
Cesium
Palladium
GUM BICHROMATE PRINT
In gum bichromate printing the paper is coated with gum arabic which carries a
pigment, and is sensitized with a bichromate. On exposure to UV light the bichromate
causes the exposed gum arabic to harden and become insoluble in proportion to its
exposure. The areas not exposed to light remain soluble.
The print is developed by floating it face down in water. The unexposed portions
dissolve taking the pigment along. The insoluble portions remain on the paper. The
print can be manipulated while developing, allowing the printer to make many local
modifications. Any watercolor pigment can be used allowing the printer to choose the
color of print. It is also possible, though very challenging to make full color prints
using multiple printing with different colored pigments and color separation
negatives.
In order to get a good print it usually necessary to multiple print, that is to coat,
expose and develop the same print repeatedly to develop a full tonal scale. This
requires some sort of registration technique. See the article Substrate Gum Method for
a method of registering Gum Bichromate prints.
Gum bichromate printing can be very demanding because of its flexibility. The final
gum bichromate image is usually somewhat soft.
Hazards
Pottasium dichromate and ammonium dichromate are moderately irritating to skin and
highly irritating by inhalation. They can cause severe allergies and ulceration, and are
also suspected carcinogens. Ammonium dichromate is flammable and unstable in the
presence of many other substances. Many pigments used are moderately to highly
poisonous, and can cause chronic poisoning from inhalation and accidental ingestion
Precautions for Gum Bichromate
Handle gum arabic carefully, avoid inhalation of dust. Wear gloves if allergic.
Wear gloves and goggles when handling dichromates. Brush rather than airbrush or
spray onto paper.
Store ammonium dichromate seperately and away from sources of heat
Wear gloves and goggles when handling ammonia solutions. Use good ventilation
Avoid toxic preservatives such as formalin or mercuric chloride
When choosing pigments, choose the least toxic. Use tube pigments rather than
powdered pigments. If powders are used avoid grinding or spraying
Wear gloves or use tongs throughout development to avoid contact with dichromates
and pigments dissolving from the gum.
Color Printing using Color Separation Negatives
by Virginia Boehm (gini@ix.netcom.com)
Making prints using color separation negatives requires the preparation of three large
negatives from the same original image, often a color slide. One exposure is made
with red filtration, one using green, and a third negative is made using blue filtration.
The three negatives are each printed on to the same piece of paper using consecutive
coatings of gum and watercolor pigments of the complementary color to the one used
when making the negative. The red filtered negative is printed on paper coated with a
blue (cyan) pigment, the green one on magenta (crimson) coated paper, and the blue
filtered one is printed on yellow.
Choice of pigments is a matter of artistic taste. Sources frequently recommend
Cadmium Yellow, Alizarin Crimson and Pthalo (Windsor) Blue. A more pastel pallet
consists of Cadmium Lemon or Light Yellow, Alizarin Carmine and Cobalt or Intense
Blue. The order in which the paper is coated and exposed can also vary. While the
usual recommendation is blue, then red, and finally yellow, I find that the reverse
often works well, particularly with subjects that are basically warm toned.
While perfect color filtration is unlikely and further negative masking frequently
required to produce complete color separation, the resultant print reproduces the
colors of the original. The steps involved in the process and the color theory involved
is outlined in "The Gum Bichromate Book, Second Edition" (Focal Press, 1991 by
David Scopick.
Substrate Gum Method
by Richard Sullivan richsul@roadrunner.com
About 15 years ago I was looking closely at some early Pictorialists gum prints that
Stephan White had in his gallery in Los Angeles. One of them caught my eye in that
the margins had not been trimmed and it was clearly a multi coated gum and yet the
registration of each coat was perfect, even though the print was @ 11 x 14 inches. I
wondered how this was possible, and then it occurred to me that perhaps the
photographer had mounted the print to stabilize it prior to printing. I surmised that
perhaps he had used a solvent based glue (shellac, etc.) and mounted it on a piece of
inert material (Bakelite or even glass). From here I went on to devise my own method
of substrating which I'll describe and then note the benefits of this method.
Cut a piece of inert thin material such as formica, heat resistant plastic, etc. I used
circuit board phenolic which I bought at a surplus store. The size should be several
inches larger than the paper to be printed on.
You will also need some N3 Bregman pins. These are thin .5 inch by 1.5 inch
stainless steel pieces with a 1/16 inch high 1/4 inch round stub protruding from one
end. The "N3" is the designation for the ones I used. You will also need some tabs,
they used to be called Berkey tabs but there are many manufacturers now. These are
mylar 1 inch by 1 inch tabs with sticky stuff on one end and a 1/4 inch hole in the
other. The pins and tabs can be obtained from a good printers (ink on paper) supply
house, I used to get them from the Seward Co. on Alvarado Street in Los Angeles.
You also will need some double backed carpet tape obtainable from any carpet store.
Here's what you do with all this nonsense. (Actually its a lot simpler than it sounds
and goes real quick as well.)
First take your paper that you want to print on and dry mount it to the center of the
substrate material. It's a little tricky since any humidity in the paper may steam out
and cause the paper to form a bubble on the board, a little practice and it'll get easy.
Degrease with isopropyl alcohol or other solvent one edge of the board next to the
paper. Cut a piece of the carpet tape a little larger than the N3 pin and peel the
backing off one side of the tape and stick it to the bottom of the Bregman pin. Trim
off excess tape from around the pin with a razor blade. Peel off the other backing and
stick it to the degreased part of the substrate next to the paper. Repeat this process
with the other pin and stick it a few inches from the other pin on the degreased margin
of the board. You now have a dry mounted piece of paper with the two pins mounted
to the board on one side. The two round stubs are the heart of the registration system
and will mate with the tabs which you will attach to the negative. I place the tabs on
the stubs of the N3 pins with the sticky side up with the stub of the pins through the
holes in the tabs. The negative is then carefully attached to the sticky stuff with the
emulsion side up. When used the negative will be turned over. This is just an easy
way to assure that the tabs will fit the registration pins (stubs). You may find that
taping an extension to the negative cut from a junk negative or piece of acetate may
be needed.
What you now have is a board with a piece of paper dry mounted to it with two round
stubs off to one side. Your negative has two tabs sticking out with two round holes to
match the stubs. Voila! a registration system.
You can now get away with murder when printing gum. Typically my students would
print 8 to 10 coats in a session on several prints. The technique that evolved was to
coat being light on pigment and underexposed. Typically an underexposed gum
develops quickly, looks beautiful, but just slides off the paper as it continues to
develop when out of the water. When substrated, you can shake off much of the water
and then dry with a hair dryer, if your power can handle it, you can use two. Keep a
pot of warm gelatin handy and size between coats.
Essentially you coat with a thin coat of pigment, develop for 2 to 3 minutes (board
and all goes in the water,) shake, dry quickly with a hair dryer. Size and dry between
coats. Repeat, building up the pigment as needed. The paper does not curl or buckle
and in a way, only one side is wet.
When finished, stick the board and print in a drymount press and get hot. Open press
and quickly peel up one corner of the paper and strip off. You may neeed to strip it off
in stages if it is large. The print can now be trimmed and remounted to a large sheet of
the same paper. The board with the pins mounted can be used over again. I have some
boards that are over 10 years old and the pins are still firmly mounted.
CARBON PRINT
A tissue is coated with a gelatine solution carrying a pigment sensitized with a
dichromate. When it is exposed to light the gelatin hardens and becomes insoluble.
The gelatin hardens only on the surface, to counteract this the exposed and washed
tissue is placed firmly on a final support and then peeled away, transferring the image
to the final support. This leaves the image flipped over on the final support and
exposes the unhardened gelatin.
The transfer tissue is the temporary support that holds the gelatin pigment mixture
during exposure. After exposure the gelatin and pigment are transferred to the final
support. There are no current manufacturers of transfer tissue. The pigment transfer
tissue can be made by hand. This makes the carbon process somewhat complicated.
A pigment tissue is made by coating a support with a mixture of gelatin and pigment
and other a number of other ingredients. After the pigment tissue has been coated it is
sensitized with a dichromate, and left to dry. The pigment tissue is the exposed to UV
light. The dichromate causes the gelatin to harden where it is exposed to light.
After exposure the tissue is soaked for a few minutes to allow the excess dichromate
to dissolve out and to allow the tissue to flatten. The tissue and final support are
placed face to face under water and aligned. The two sheets are then carefully pulled
out of the water, placed on a flat sheet (glass) and lightly squeegeed together.
The sheets are then weighed down for about 20 minutes. The two sheets are then
placed in water at about 40 degrees C. The soluble gelatin and pigment will begin to
ooze out. After another minute, carefully peel the pigment tissue off the final support.
At this point there is no visible image on the final support, it consists of a mass of
undissolved gelatin and pigment.
The final image is developed by agitating in all directions the final support in water in
a number of baths, until the image is fully developed. The image develops by the
unhardened unexposed gelatin dissolving in the water. The exposed gelatin is
hardened by the dichromate and made insoluable in water. After development is
complete the image is immersed in cold water to harden the gelatin. The resulting
image is made up of only gelatin and pigment, making the carbon print one the most
archival processes.
Hazards of Carbon Printing
The sensitizer contains pottasium or ammonium dichromate, which are both
moderately irritating to skin and highly irritating to the respiratory system.
Dichromates can cause skin and respiratory allergies and ulcerations. They are both
suspected human carcinogens. Ammonium dichromate is flammable and unstable
when in contact with many materials. The hardening bath conatins formalin which
ismoderately irritating to the respiratory system, causing severe skin and respiratory
allergies including asthma. Formalin is poisonous if ingested and is a suspected
human carcinogen.
Precautions for Carbon Printing
Wear goggles and gloves when handling pottasium dichromate or sodium dichromate.
Mix powders in a fume hood or dust box, or used an approved toxic dust mask.
Keep ammonium dichromate away from sources of heat and store seperately from
other chemicals.
Wear goggles and gloves when handling formalin baths. For large amounts use a local
ventilation system.
ULTRASTABLE
The UltraStable process is a direct descendant of the original tricolor carbon process.
While the original process used several transfers and manual registration techniques,
this new incarnation makes the possibility of obtaining beautiful permanent color
images much more easily.
The UltraStable process makes use of pre-sensitized pigment sheets. There is no
messy and dangerous handling of dichromate and the shelf-life of the materials is
about one year at room temperature or longer if refrigeration is used.
This process is relatively new. A computer is used to generate color separation
negatives from the original image. The original image is first digitized by using a high
resolution scanner. Computer software is used to produce four half-tone separation
negatives of the same type used in the printing industry. The closer the dots are
printed together the darker the image appears. This is the same technique used to print
images in books and newspapers only much more refined. One can get wonderful
separations and screened negatives with a high resolution scanner and printer. The
process can also be (and is) used with optically produced continuous-tone negatives
The exposure of the pigmented sheets and the development is very similar to carbon.
The main difference between the Ultrastable process and the traditional carbon
process is that the former uses convenient pre-sensitized pigmented sheets on
dimensionally stable polyester sheets so that automatic registration is possible. The
main drawback is that screened negatives are required and most people will have to
use a service bureau to have them made.
There is more information available on UltraStable in the book: The Permanence and
Care of Color Photographs : Traditional and Digital Color Prints, Color Negatives,
Slides, and Motion Pictures , by Henry Wilhelm with contributing author, Carol
Brower.
Ultrastable materials and information are available from:
UltraStable Color Systems
500 Seabright Ave. Ste. 201
Santa Cruz
95062 California
USA
Tel 1-408-427-3000
. Fax1-408-426-9900
CARBRO PRINT
In carbro printing a pigment tissue similar to that used in Carbon printing is brought
in contact with a bromide print. The gelatin in the pigment tissue loses its solubility
through the chemical reaction between the sensitizer on the pigment tissue and the
silver in the bromide print. The tissue is then transferred to the final support and
developed in the same manner as a carbon print.
The advantages of a carbro print is that the pigment tissue is never sensitive to light
and a UV light source in not necessary since the bromide print is made using
traditional silver-gelatin methods.
Most bromide prints made today are coated with a hard surface to protect the fragile
gelatin underneath. It is not possible to use these papers in carbro printing. Common
unsupercoated papers currently available are: Kodak Polycontrast Rapid RC matte
surface, Luminos RD Matte Bromide, Agfa Portriga Rapid No. 118, SupreBrome
Royal Portrait Matte Paper, Ilfobrome Semi-Matte paper.
Hazards of Carbro Printing
The main hazardsof carbro printing result from exposure to the bromide developer
and to the sensitizer for the carbon tissue. The developer can be a skin irritant causing
allergies. The sensitizer for carbon tissue contains potassium dichromate which is
moderately irritating to the skin and highly irritating by inhalation. It can causeskin
allergies and ulceration. It is also a suspected human carcinogen.
Precautions for Carbro Printing
Use the least toxic bromide developer.
Do not heat or add acid to sodium thiosulphate
Wear gloves when handling dichromate sensitizer. Mix in a fume hood, glove box or
wear an approved toxic dust mask.
Avoid inhalation of pottasium bromide powders.
Wear gloves when handling solutions during transfer and development of the carbon
tissue to avoid skin contact with pottasium dichromate and pigment suspended in
gelatin.
BROMOIL PRINT
by Rita Carnes, Albuquerque, New Mexico
rita@indirect.com
Bromoil printing begins with a normally developed silver print. A non-hardening
developer, such as amidol or Ethol LPD, is preferred for processing. Subsequent
bleaching and tanning of the print removes the silver and results in selective
hardening of the gelatin. In other words, the non-hardened areas of the print (the
highlights) will absorb water and repel ink. The hardened parts of the print (shadows
and mid-tones) will accept ink, resulting in a positive image resembling the original
print. The advantages of bromoil are that (a) it allows a considerable degree of control
over final image quality and (b) it is permanent.
The bleaching/tanning solution is made of distilled water (1000 ml), into which 70 ml
of 10% solution copper sulphate, 70 ml of 10% solution potassium bromide, and 30
ml of 1% solution potassium dichromate is added. This solution will bleach out about
a dozen 5x7 prints.
The ink used in bromoil printing is similar to lithographic ink. Hard ink is used
initially, followed by soft ink, although the former alone will result in a lovely effect
resembling etching. Brushes are specially-made of either hog, bear or fitch hair. A
source for materials is provided at the end of this article.
The inking process involves first soaking the matrix (what the original print is called
after bleaching and tanning) in water to induce the differential swelling of the gelatin.
Test strips are used to determine optimal soaking times, starting with five minutes and
continuing up to about 20 minutes. The test strips should be completely free of
surface water before applying ink. The strip that accepts the ink most easily, with
good buildup in the dark areas and clear highlights, will determine the proper soaking
time.
The matrix is then soaked for the determined time and the surface water removed
(using a damp chamois). The matrix is then placed upon a support and ink is applied.
The inking process requires considerable practice to master the technique and
involves lightly coating the surface, pushing the ink into the shadows and mid-tones
and out of the highlights. The matrix may have to be re-soaked several times during
the inking process, especially if resin-coated paper is used. The final print is allowed
to dry for several days before matting and framing.
Bromoil supplies and materials can be obtained from David W. Lewis, 457 King St.,
Box 254, Callender, Ontario, Canada, P0H 1H0.
References:
History and Practice of Oil and Bromoil Printing, by Luis Nadeau
The Art of Bromoil and Transfer, by David W. Lewis
The Keepers of Light, by William Crawford
Hazards
Potassium dichromate and potassium bromide are moderately irritating to skin and
highly irritating by inhalation. They can cause severe allergies and ulceration, and are
also suspected carcinogens.
Copper sulphate??
Ink??
Precautions for Bromoil Printing
Use the same precautions followed in silver printing.
If amidol is used as the developer, then mix the solution outside the darkroom since
the powder can become airborne and contaminate paper, resulting in purple stains.
POLAROID TRANSFER
The Polaroid transfer uses Polaroid peel apart color films in an unconventional
manner. The Polaroid pack is peeled apart during processing, the positive image is
transferred to an alternative surface. The surface the image is tranfered to imparts a
different quality to the image. A receptor sheet is prepared, this will hold the final
image. If paper is being used it is thoroughly soaked, other media can be used such as
silk and other textiles.
The Polaroid negative is exposed, recording a new image, or by projecting a
previously made slide onto the Polaroid. The film is processed in the pack as normal
except the film is peeled apart after about 10 seconds. The negative containing all the
dyes is then placed on the prepared receiving sheet. The negative is then firmly
pressed onto the receptor sheet using a roller or your hands. It is critical to use even
pressure. After waiting 90 seconds to two minutes the negative is peeled off the
receptor. The dyes have now been transferred to the recieving sheet transferring the
image to the receptor sheet. The quality of the transferred imaged depends on the
method of transfer and the nature of the receptor sheet. A wide variety of papers and
textiles can be used for receptor sheets.
Polaroid makes a variety of peel apart films in different sizes. Transfers will not work
with black and white polaroids or with the SX70 style instant polaroids or other
"integral" film types
Polaroid has produced a publication on Polaroid Transfer. They can be reached at
Toll Free at 800-225-1618
Hazards of Polaroid Transfer
The main hazard of Polaroid films is exposure to the highly caustic processing jelly,
which contains sodium hydroxide or pottasium hydroxide. It remains at a high pH on
the discarded portion (the non-image and negative area) for up to two hours. It is
highly corrosive to the skin eyes and mucous membranes.
Precautions for Polaroid Transfer
Avoid skin or eye contact with residual processing fluid.
Dipose of wet negatives in a closed waste container to prevent further contact.
If children chew or ingest film flush with water and contact a poison control center.
MY METHOD FOR CASEIN BICHROMATE
By Ernest J. Theisen
The founder of the New Pictorialist Society, Ed Romney mentioned in one of his
articles in the Bulletin, that a fellow named Franklin Enos was making prints using
the Casein Bichromate process and urged any of us who were interested in trying the
process to write to Franklin for information.
Franklin and I started a correspondence that continued for several months. He sent me
complete instructions on the process including small jars of pigment and powered
casein (Sodium Caseinate).
At the start of this "training session" Franklin composed a still life of all the
ingredients and equipment required, photographed the arrangement, prepared a casein
print of the negative and sent it to me.
I made prints following his instructions and sent them to him for critique and
evaluation. Gradually I learned how to make passable prints relying greatly on the
master's help and patience.
Franklin was continually experimenting with formulas and methods, continuing to
learn the process. He always referred to his formula as his "current formula" implying
constant refinement. He always encouraged me to use his methods only as a starting
point and urged me not to attempt to duplicate his printing style but to use the process
for my own creative endeavors.
Franklin Enos died September 30, 1983, in his eighty seventh year. As Len
Oppenheimer wrote in his memoriam for him in the January/February 1984 AVISO,
"Franklin, although he never would admit to mastery of a process, was in truth the
master of many control processes but his great love was the Casein Process which be
had refined to as much of a science as a photographic process can be".
In the fall of 1984 Stan Cummings gave me a formula for making Ammonium
Caseinate from powered milk. I had not been working in the Casein Bichromate
process for a couple of years because I could not find a source for Sodium Caseinate
(casein in power form). During this time I had been working Multiple Gum
Bichromate using Stan Cumming's formulas and techniques. I learned that it was very
easy to make casein from powered milk and I started my experiments combining
Stan's techniques with my home-made Ammonium Caseinate.
Powered Sodium Caseinate is difficult to dissolve in water based solutions. I had
success making my own colloid, which I guess would be called Ammonium
Caseinate, although I am not a chemist so I'm not sure if that is right.
The Casein Bichromate Process is very similar to the Gum Bichromate Process. In
fact as far as a process is considered, it is almost identical. While the process is the
same, the look of a Casein Bichromate print and a Gum Bichromate print is quite
different.
a)Gum Bichromate prints have a transparent watercolor appearance where Casein
Bichromate prints resemble gouache.
b) Casein Bichromate prints have a longer scale than Gum Bichromate prints. A fairly
long series of values can be achieved with one impression where Gum Bichromate
prints require several runs or "multiple impressions." Franklin Enos could make a
Casein Bichromate print containing a range of tones approaching a carbro print with
one run. (I have never been able to accomplish this. I need at least two impressions to
get highlight, midtone and shadow tones.)
c) Casein is more forgiving than Gum. The wet image is tougher, allowing more
vigorous manual intervention with strong water spray and direct brush work. Gum
Bichromate prints require much more care and delicacy in soaking and clearing.
Casein Bichromate prints withstand the rigors of multiple printing better than Gum
Bichromate prints.
d) Ammonium Caseinate is much easier and quicker to make than liquid Gum Arabic.
The best Gum Arabic is made from "chunks" of Acacia tree sap. It must be dissolved
slowly in water, over several days and then filtered to remove traces of Acacia tree
bark, elephant hide and rhino horn.
The Casein Bichromate process is not "better" than the Gum Bichromate process. It is
just different enough to make it interesting and worthwhile to learn.
I will describe my method and you can jump off from there;
Briefly it goes like this,
a) I make a colloid mix, in this case it is Ammonium Caseinate.
b) I made a "basic mix" which is the colloid mixed with pigment.
c) I made a coating mix which is the basic mix combined with water and the
sensitizer.
d) I coat the paper, expose and develop the print.
1. The Colloid. Mix 1/4 cup non fat powered milk with 8 oz. hot water. Mix 3 cc
Glacial Acetic Acid with 7 cc water. Add to the milk mixture. A curd will form
immediately. Separate the curd from the whey using a fine strainer or a piece of fine
mesh and gently wash the curd under cool water until the acid smell goes away. This
should take five minuets. Put the washed curd in a beaker and add 75 cc of household
Ammonia. Buy a fresh bottle, it loses its strength quickly once the bottle has been
opened. It takes about 24 hours for the curd to dissolve in the Ammonia. Put it in a
small jar after it is completely dissolved. I never add any preservative. I use it before
it goes off.
2. The Basic Mix. For pigments I use Winsor Newton transparent watercolors. I have
a gunpowder scale so I measure in grains. Each color requires a different amount of
pigment. Not all colors work well. As an example Chrome Oxide gives unpredictable
results. It stains and does not react well with Ammonium Bichromate. I had best
results with Lampblack. I do not know how you measure so you will have to
experiment. As is true in the gum process, too much pigment causes staining.
Mix 40 grains or 2.6 grams WN Lampblack to 50 cc of the Casein. Put this in a small
jar.
For other WN colors try these proportions
Color
For 50 cc of colloid
Alizarin Crimson
52 grains or 3.5 grams
Thalo Blue
40 grains or 2.6 grams
Cadmium Yellow
60 grains or 4 grams
Hansa Yellow
12 grains or .8 grams
Burnt Sienna
60 grains or 4 grams
Burnt Umber
60 grains or 4 grams
3. Sensitizer. Either Potassium Bichromate or Ammonium Bichromate (AB) will
work. I used Ammonium because I had it. Mix a saturated solution of AB. You don't
need much so don't mix much. Ammonium Bichromate is faster than Potassium.
4. Coating mix. I always mix the same quantity of coating mix; 15 cc. I then vary the
proportions of the ingredients for best results. This is a standard mix for lampblack.
This makes 15 cc of coating mix. Mix 4 cc of basic pigment mixture with 7 cc of
distilled water (always use distilled water for all of these processes) with 4 cc of
saturated AB to make 15 cc in all.
I can coat five 8 x 10 pieces of paper with 15 cc of this mix. This is a thin coat. I
usually make from two to five runs on a print. More than that and I get staining no
matter how thin I make the mix. You will vary the proportions for your own best
results.
5. Exposure. This is a function of your light source. Start with an exposure you use for
gum and go from there.
6. Development. Soak the exposed print is a tray of room temp water for ten to fifteen
minutes. This softens and swells the colloid and clears most of the Bichromate out.
Place the print in a sink in a tray of water and spray with a hose with a spray
attachment on the print, through the water covering the print. This allows you to start
with a gentle development spray. Depending upon the progress of the development
you may increase the spray force to the point of spraying directly on the print surface.
For stubborn prints, try this; following the initial soaking, transfer the print to a tray
containing a weak sodium carbonate solution. I mix two teaspoons of sodium
carbonate to a quart of water. Soak this for ten to fifteen minutes, then spray to
develop. If this does not work, discard and start over with less exposure.
That's about all I can tell you. I assume you know a method of registration for making
multiple runs. Give it a go and let me know how you make out.
DYE TRANSFER MATERIALS AND PROCESSES
By James Browning
My name is Jim Browning, and I am a fine-art photographic printer, and consultant in
the imaging business. I got interested in large format photography in the mid eighties
in a big way. I moved my engineering career toward imaging technology as a result of
my passion for photography. In 1990, I decided to leave Silicon Valley, and try my
hand at printing in my native state of New Hampshire.
My interest in Dye Transfer has always been in the back of my
mind, since my Uncle Don and Aunt Helen Browning had a dye
lab from the forties through the eighties. I saw some great
prints, Yousef Karsh portraits of the Pope, and the British royal
family, and famous celebrities of the day, as well as prints of
architectural images by Scott D'Arazian. The people in these
prints always seemed alive, and not flat like most
photographic prints of the time.
So, it was with the idea that I could make really great prints
myself, and perhaps improve on the venerable old Dye
Transfer process. Initially, I setup a lab to do both Dye
Transfer and Cibachrome printing. In the early part of this
decade, computers were still relatively expensive, and
processing huge files was not something I could afford. I
decided to build a laser scanner / film recorder for use in
making correction masks for printing Ciba prints. I built the
system, which I used to scan the original transparency, edit
the image, and write out a contrast controlling mask onto pan
masking film. My original intent was to extend this to a color
correcting mask on transparency film, but I never started this
phase of the project. I got quite good at printing the Cibas,
and the laser masking system worked very well. In 199 5, the
new faster Power Macs became available, so I decided to move
up to high resolution imaging. I developed the equipment to
scan and print onto 8x10" negative film at relatively high
resolution, about 150mb. The results are really good, I was
able to print images I was never able to master before, using
Live Picture was a godsend to my ability to print.
I was still unhappy with the materials, either type C, or
Ilfochrome (Cibachrome). My frustration lied in the limited
gamut, or saturation of the dye set built into conventional
materials. I remembered the quality of the prints my Aunt and
Uncle used to make, their vibrancy, depth, and realness of the
people's faces. The prints on conventional materials were
certainly beautiful, but they did not stir the feeling of reality I
had seen in a dye print, emotionally, they were flatter.
I did make some dye prints in the conventional manner. I
spent quite a bit of money setting my lab up with registration
equipment, and got quite good at making dye prints for
myself. I quickly realized that the process could really be
simplified and more control could be had by digitizing the
image - dye printing does not allow simple dodging and
burning controls, and this made for a certain level of
complexity that I figured had to be eliminated. About this
time, Kodak reaffirmed their commitment to Dye Transfer',
which is code for dropping it like a hot potato. Which of
course, they did.
I decided that I couldn't give up, just because the materials
were no longer available. I would have to make them myself,
to avoid this situation again. I also needed to make the
process commercially viable, which means competing against
other methods of producing prints, such as Iris. So, my goal
became to make the materials, and reduce my film costs
(Kodak raised the prices of the materials towards the end, to a
point where the process was no longer profitable). It took two
years, but I now have a great matrix film, which I use in
conjunction with my laser recorder to make dye prints.
The process goes as follows: first I scan the transparency into
the computer using my laser scanner. I then retouch out dust
and scratches using Photoshop. I then use Live Picture to do
critical color correction, and localized manipulation of tone
curves, dodge and burn. I then place 8x10" Tmax film on the
registration pins of the laser recorder, and expose the red,
green and blue separation negatives in sequence. I develop
them all at the same time. I then load up the Saltzman
enlarger with the seps, and print onto the matrix film, and
develop the matrices. The digital process eliminates the need
to make two color correction masks, and three highlight
masks. All exposures / development times, and all aspects of
the transfer process are kept fixed. I only use small
adjustments of the transfer to tweak the print the final bit, a
very necessary thing to do to get a fin e print, and only
available with the Dye Transfer process.
Dye Transfer works by creating a relief image in gelatin. The
thickness of the gelatin on the matrix is proportional to the
amount of exposure the area receives. This is accomplished by
exposing the matrix through the base. A yellow dye is
incorporated in the emulsion which absorbs the blue light to
which the film is sensitive. The exposure proceeds to a greater
depth into the emulsion with greater exposure. The film is
developed in a pyro tanning developer which cross-links the
polymers of the gelatin in exposed areas, and 'hardens' it, or
makes it insoluble in water. The film is then washed in very
hot water, and the unexposed gelatin washes off. The matrices
are then soaked in dye baths, and the dyes migrate into the
gelatin relief image on the matrix. The matrix is then rinsed,
and then rolled into contact with the receiver sheet. The dye
transfers from the matrix to the receiver. This is repeated
three time, Cyan, Magenta, and Yellow transfers create a print,
with a very strong and neutral black D-Max, and a D-Min
(highlight) at the paper white. Many controls can be applied
during the transfer process by varying the chemistry of the
solutions - color balance and contrast are fine-tuned at this
time. You can even paint dye onto the matrix (mat) by hand,
and transfer again to beef up the color in a specific area. The
prints are easily bleached, and retouched - an important
aspect of a dye print.
The results reflect the process. I use the best aspects of the
digital techniques, combined with the totally smooth
continuous tone characteristics of the Dye Transfer materials.
The special qualities of the prints can vary from extremely
subtle rendering of delicate pastels, with all of the nuances of
tonality preserved, to vivid and bold images which are only
available with the pure dyes evenly co-mingled in the paper.
The process avoids the harsh appearance of an ink jet print,
and has no patterning or grain imposed on it. The shadow DMax can be very high, but with sufficient light, detail is seen
right down to D-Max, similar to a well made silver gelatin
print. Since the dyes can be transferred to any gelatin coated
smooth surface, I use a variety of high quality fiber surfaces,
and have transferred to gelatin sized Arches papers - without
loss of image quality.
My work these days is concentrated on identifying and testing
dyes selected for specific purposes. I plan to offer prints with a
dye set matched to the image, since no single set of dyes will
render all colors optimally.
This is a complete description of how to make your own Dye
Transfer printing materials, including a formulation for the
matrix film, coating techniques, formula for a developer, and
preliminary dye formulations. I am making this public in the
spirit of furthering the cause of the Dye Transfer printing
community. Please feel free to distribute this information.
Notice: Use caution when handling the chemicals listed. In particular, use gloves,
goggles, and have adequate ventilation when handling the Silver Nitrate, Gold
Chloride, Oxalic Acid, and Pyrogallic Acid, and Acetic Acid. These chemicals are
hazardous, and should be used with proper techniques.
Browning / Adams Matrix film Formulation
The following matrix film was developed by me (Jim Browning) with the generous
help of Rae Adams. This is a conventional Iodobromide emulsion, which has been
adjusted for moderately high contrast, but without sacrificing tonal linearity. This
emulsion works quite well. You will have to develop your seps to a higher gamma
than when working with the Kodak materials. The film is about the same speed as the
old Kodak matrix film.
Making the emulsion requires a system for heating a five liter container (Stainless),
and maintaining the temperature accurately. A burette suspended over the container is
used to slowly drip solution A into solution B over long periods of time. A propeller
stirrer is also mounted over the reaction vessel, and run at slow speed.
The following formulation (Trial # 19) is for four Liters of emulsion:
Solution A:
Potassium Bromide
168 g
Potassium Iodide (5% solution)
62.4 ml
Inert Gelatin
160 g
Distilled Water
3500 ml
Solution B:
Silver Nitrate
160 g
Distilled Water
500 ml
Solution C:
Sodium Thiosulfate (0.1% solution)
10 ml
Gelatin
20 g
(gelatin added directly to the heated emulsion)
Solution D:
Potassium Bromide (1% solution)
10 ml
Manganous Sulfate (1% solution)
10 ml
Acid Yellow Dye # 23 (Tartrazene)
2.0 g
Saponin (1% solution)
2.5 ml
Distilled water
50 ml
Emulsification / Physical ripening:
Add B (at 55 deg C) to A (at 55 deg C). Use a burette over a heated beaker holding
solution A at 55 deg C. Stir the solution using a paddle mixer. (approx. 200 rpm).
Temperature must be controlled to 1 deg. C using a temperature controller and hot
plate.
Addition as follows:
Add 10 ml of B to A in 5 seconds.
Wait 1 minute
Add 245 ml of B to A over 4 minutes.
Wait 10 minutes
Add 245 ml of B to A over 5 minutes.
Ripen additional 15 minutes
Immediately chill the emulsion using an ice bath. Chill until the
emulsion is very solid, whack the side of the container, there
should be a distinct 'jiggle' feeling.
Cut the emulsion into 'noodles' 1/4" crossection. Force the
gelatin through a 1/4" grid constructed from fishing line. Wash
using distilled water for 4 hours. Change water frequently. Use
at least 1 gallon of distilled water.
Note - In order to match the speeds of several sheets of film, it is necessary to
sensitize enough emulsion for the full batch. Multiply the Solution C and Solution D
quantities by the number of sheets to be coated, and sensitize and final prep the entire
batch at one time. Filter the emulsion two times, once with 40 um filter paper, and
again using 5 um filter paper. Use a vacuum filtration system. Divide the emulsion
into separate 500ml batches, and pour into one liter stainless beakers with covers.
Refrigerate until fully gelled. To coat, remelt the emulsion in one container, and coat.
Follow the same procedure for all sheets.
Sensitization (Digestion or Chemical Ripening).
Remelt the emulsion, heat to 60 deg. C. Add the 20 g gelatin to the mix, stir until fully
dissolved. Add Solution C, mix thoroughly. Stir rapidly for 1 hour while maintaining
temp at 60 deg C.
Control temp to 1 deg. C. This step should be stirred vigorously, initially moving the
paddle stirrer around in the emulsion to thoroughly mix. Cover the emulsion with
aluminum foil while stirring to prevent fogging from t he safelight. The emulsion's
speed increases 1000 times during the sensitization process.
Final Prep:
Add solution D, mix. The Tartrazene dye is used to absorb blue light to cause the
depth penetration exposure effect, and to minimize scattering. A wetting agent
(saponin) is added to promote even coating.
Coating: Coat 500 ml over a 30" X 40" area. At 100 deg f.
Setting: Set at less than 50 deg F for 10 minutes to gel
emulsion. Note: the emulsion will reticulate at this point if it is
too thick.
Drying: Dry in a dust free enclosure for 2 hours at 70 deg F,
50% R H, moving to 85 deg. F 30% RH for 6 hours.
Use care when making the emulsion. Completely scrub the mixing vessel, beakers,
stirring paddle, stirring rods, etc. Use soap, and an abrasive scrubber. Rinse
thoroughly, final rinse with distilled water. Filter the emulsion with 5um filter paper
using a vacuum filter before coating. A filter must be installed in the coater, placed in
a position before the emulsion passes through the slot. Thoroughly clean all mixing
vessels, and other utensils as you go, and carefully clean the coater after a coating run
to prevent buildup of gelatin which would re-melt into subsequent emulsions. The
coater must be repeatably rinsed with hot water between uses. All operations are best
carried out using the light of a sodium safelight, which provides adequate light for
working for long periods of time.
About Gelatins:
The gelatin greatly affects the sensitization of the emulsion. In the past, less refined
gelatins which contained sulfur compounds were used. These are termed 'fast'
gelatins, and they sensitize the emulsion without the need to add a thiosulfate
sensitizer. The problem with this is that each batch of gelatin will have a different
effect. In modern emulsions, either a highly refined inert gelatin is used, or the gelatin
is artificially synthesized. This allows a controlled sensitization by addition of sulfur
and gold compounds to the mix. I find that the lot controlled Kind and Knox
photographic gelatins work very well. They harden well in the tanning developer,
withstand vigorous washoff, have low fog characteristics, and absorb and transfer the
dyes readily. Use of other gelatins will probably yield very different results!
The Dyes I am using are as follows:
HL reducer: 20 g Sodium Hexametaphosphate in 1.0 L Dist. Water.
Cyan:
Acid Blue # 25 1 g
HL Reducer 10 ml
Set pH to 4.80
Magenta:
Acid Red # 289 1.5 g
HL Reducer 100ml
Set pH to 7.00
Yellow:
Acid Yellow # 23 3.2 g
HL Reducer 10 ml
Set pH to 4.00
Mix the dyes with about 100 ml of distilled water and heat to near boiling. Add a few
crystals of Thymol as a preservative. Add most of the remainder of water. Titrate the
solution to the specified pH using Acetic acid and Trieth. Be careful not to let
magenta dye solution become more acidic than pH 4.0 at any time, as this will ruin
the dye. Top off with distilled water to make 1L of dye. Filter before use. Check the
pH frequently, and adjust. Filter frequently during use. You may make up a more
concentrated replenishment dye, which is added as the dyes are removed from the
working solution. Thanks to Andy Cross for determining these dye mixtures.
Developer:
Expose the film through the base (Emulsion down), and develop in the following
tanning developer:
Solution A:
Benzoatriazole
2.0 g
Oxalic Acid
8.0 g
Metol
28.0 g
Pyrogallic Acid
30.0 g
Water to make
4L
Solution B:
800cc by volume of Sodium Carbonate to make 4L of
liquid.
Mix 1 part A to 2 Parts B for normal contrast, develop for 2 minutes @ 68 deg F.
Make sure you presoak the film for 1 minute. Rinse film in cold water for 30 sec, and
fix in a non-hardening fixer for 5 min. Wash off unhardened gelatin using four of five
vigorous rinses at 120 deg. F. Dry. Soak matrices in 120 deg. F water for 1 minute
prior to soaking in dye for at least 5 minutes. Transfer the image for at least 5 minutes
for the cyan and magenta, and 2 minutes for the yellow.
Condition the paper in paper conditioner for about 15 minutes before transferring the
image. This is Bob Pace's formulation, I haven't tried it.
Triethanolamide
60 ml
Glacial Acetic Acid
19.4 ml
Ethylene Glycol
100 ml
Water to make
4L
Check pH and adjust to 6.0.
For a complete discussion making separations, exposing and developing the matrix
film, and rolling the prints and retouching, please refer to the books mentioned. This
area is where DT printing really shines, and printers develop their own unique
methods for controlling the print during the rolling process.
Some of the controls you can add to the first rinse are:
Acetic acid
increases contrast of print.
Sodium Acetate
decreases contrast of print.
Sodium Hexametaphosphate
Reduces amount of dye in the highlight (Highlight
reducer)
Also, you can increase or decrease the pH of the dye baths for large changes in
contrast. Some people actually paint the dyes onto the matrices, and re-transfer to
increase saturation in a local area. The opposite of this is to squirt the Sodium Acetate
solution at the matrix to leach out some dye to remove unwanted color. The print is
easily retouched, one of the best features of a dye print.
About Coating:
I have built a sheet coater which is very simple in operation. I had a large piece of
aluminum precision ground jig plate (50" x 34" x 1") machined with vacuum
channels, and anodized for corrosion resistance. This plate is VERY flat. This is
called the platen, and it holds the film flat for coating horizontally. The platen is
mounted on SS screw leveling feet, placed in a SS 36 x 60" sink. I use a machinist's
level to get the plate very level. The slot coater consists of a 34" x 2" x 4" aluminum
piece which has a 3/4" slot milled out of the center, which forms a chamber to hold
gelatin. On the bottom of this body two triangular 'jaws' are mounted, which are
adjusted using a feeler gauge to set a 5 mil gap running a full 32 ". On the top of the
coater I have mounted three solenoid valves, and three funnels. The coater is mounted
on four precision wheels, and the assembly is driven across the platen by timing belts,
sprockets on shafts, and a DC motor which pulls on both side s, for a very smooth
motion.
In operation, I first cut a 50 x 34" piece of 0.007" Melenex 583 (ICI polyester film
with a special coating which accepts aqueous coatings), place it on the platen, turn on
the vacuum, and use the DT roller to roll out any air pockets. Previous to mounting
the film, I use a sprayer system placed in the sink beneath the platen to spray hot
water (100 deg. F). This raises the temperature of the platen so that the emulsion will
spread evenly. I then load the funnels with equal amounts of emulsion (three funnels,
back, center, and forward are used to feed the emulsion evenly into the coater
chamber). I then close the dust cover over the sink, which has a positive pressure
supplied by a small HEPA blower. I then push the button which opens the solenoids,
which pours some of the emulsion into the coater, I then start the coater moving about
1" per second. I watch the bead as the film coats, and add more emulsion when the
bead starts to thin. This control s the flow well. When the coater reaches one end, I
reverse the coating direction, and 'doctor' the emulsion with the coater blade formed
by the slot jaws coming to a point 0.015" above the film. This tends to even the
emulsion further, and remove any bubbles (rare). I then turn on cold water to the
sprayer (50 deg F) for about 10 minutes, which chills the platen, and causes the gel to
set. I then turn off the vacuum pump, open the dust cover (make sure you use full
body tyvek overalls to limit dust), lift the sheet out of the sink, and carefully tack it
onto a drying frame, and place it horizontally inside a laminar flow HEPA filtered
dryer. I use a Clestra Cleanroom Super II 2' x 4' HEPA filter blower module, which
feeds an enclosed area 2' x 4' x 4'. O n the front of the dryer cabinet is a light tight
door, which is made from light baffle panels which allow the laminar flow air to move
out of the cabinet without restriction. Drying takes a long time, usually 6 to 8 hours,
and I dry 8 sheets at a time.
A simpler method of coating should work well with smaller sheet sizes. Make an
aluminum blade longer than the width of film to be coated. The blade can be
rectangular in crossection, with a triangular point, or it could be a simple cylinder.
Wrap a wire around the blade tightly over the full length. By adjusting the gauge of
the wire, you can control the amount of emulsion passing through the gaps between
the wraps, thus controlling the emulsion thickness. The emulsion and film should be
hot enough to allow the emulsion to flow after doctoring it with the blade. Pour a
supply of emulsion in front of the blade, and draw it through the emulsion, and over
the full length of the film. The ideal thickness of the emulsion will b e enough to
allow heavy exposure of the matrix film without having the image appear appreciably
during development. A too thick emulsion will reticulate when chilled or during
drying, which will pattern into the image. A too thin emulsion will 'print through', and
the rough surface of the film will texture the image, as well as limiting the DMAX of
the print. Start with 100 ml of emulsion for a 16x20" film.
Tips:
The dyes transfer very well, but as with all matrix film transfers, you need to maintain
the temperature at least at 70 deg. F, with higher temperatures working better. The
magenta dye does have a tendency to stain the fil m base slightly, but this should not
affect the image. It also may be necessary to use an ammonia / calgon matrix cleaner
on the magenta matrix to remove the last bit of dye. highlight clarity may be
controlled by using a small amount of the highlight reducer (Sodium
Hexametaphosphate) to get the clearest highlights, near paper white. Use a good
quality fiber based paper - I have used Ilford Multigrade FB, fixed out with a nonhardening fixer. I have also used Arches hot pressed paper which I treat with a silic
one water repellent, and then size with gelatin, and harden. You may mordant the
paper with an aluminum salt, but the image transfers well, is sharp, and has good
water fastness without the use of a mordant.
Materials Cost:
The cost of materials is about $8 per sheet of 30x40" film, most of the expense is in
the silver, I buy the inert photographic gelatin from Kind and Knox in minimum 25
LB lots costing $ 10 / LB, and the polyester film cost about $ 0.50 / foot of the 50"
wide rolls. The Silver Nitrate is from First Reaction at $ 277.00 / Kg.
About making Seps:
I am creating my separations digitally using a laser based film scanner / film recorder
I designed and built a few years ago. I typically use 150mb files, which make 20x24"
prints which are completely sharp, and show no digital artifacts. The recorder both
scans the originals (Up to 150 l/mm) and records onto 8x10" film (EPN, VPS, TMX).
The film is held on registration pins, which allows exposing three seps in perfect
register.
Alternately, seps can be made by exposing TMX (Tmax-100) film using red, green,
and blue filters. Red and Green exposed color correction masks should be used when
making the seps. Develop the seps to a higher gamma than the old Kodak film, Dmax
should be about 1.50 above base fog. Make a highlight bump mask with about a 0.30
density which records only the highlights. Print each sep with it's associated highlight
mask onto the matrix film. Develop in the tanning developer. The masking for this
dye set will be different than the old Kodak dyes, but I haven't yet determined the
correct masking for this dye set. I'll supply this information when I have it.
Some Phone Numbers:
Unique Photo 800-631-0300 (best prices on film - use TMX for
seps)
VWR Scientific 800-932-5000 (General chemical supplier)
Photographer's Formulary 800-922-5255 (General
Photographic chemical supplies)
Condit Mfg. 203-426-4110 (Warren Condit) Makers of pin
registration equip.
Carolina Color and Chemical 704-333-5101 (Supplier of Dyes)
ICI 800-648-1926 (maker of Melenex polyester film stock - I
recommend Melenex 583, this doesn't pick up dye, and has an
anti-static coating on the back.)
First Reaction 603-929-3583 Best price on Silver Nitrate.
Specializes in compounds of precious metals.
Kind and Knox - 800-223-9244 (maker of Photographic
gelatin)
Bob Pace 11534 Francisco Pl. Apple Valley, CA 92308
619-247-0795. E-Mail: BPace10552@aol.com Bob is a leading
expert in dye printing, and has helped many in the past with
his newsletter Keeping Pace, which unfortunately, he has
discontinued. Ask Bob about his Dye Transfer book, and back
issues of Keeping Pace.
Dr. Jay Paterson 713-768-4581 (head of Dye Transfer Co.
Houston) They are making matrix film for sale. I have had a
chance to test this film, and I find that it works quite well.
They also have a very nice paper. They are still working on a
dye set at the time of this writing (Nov '97), but they should
be available soon.
You should try to buy the book :
The Dye Transfer Process by David Doubley. Condit used to sell this book.
If you need some advice about DT printing, or matrix film coating, please feel free to
contact me:
james.browning@valley.net
Digital Mask
187 Stevens Rd.
Lebanon, NH 03766
603-448-6241
PRINTMAKING
Etching . . Ultraviolet exposure . . Etched plate . . Etching papers and Japanese washi
Prints are made in limited editions from inked plates pressed against special papers.
With woodcuts and lithographs, the ink is transferred from a raised or treated surface.
To make an etching, ink from the incised lines or points of a copperplate is pressed
into specially prepared etching paper while the copperplate travels on a bed between
the two rollers of the etching press. Gravure prints, also known as photogravure,
heliogravure, or gravure a l'aquatinte, are a type of etching with aquatint ~ where the
image is created from a photographic source and realized in permanent ink on paper.
The aquatint ground, consisting of very fine asphaltum particles fused to the
copperplate, creates minute unetched 'lands.' In the crevices between these 'lands,' ink
remains and forms the image in a variety of tones corresponding to the depth of
etching.
The variable depth of the etched copperplate is one of the unique qualities of a
gravure print. This is made possible by the use of sensitized gelatin as an etching
resist. Etching resists are usually binary ~ they either resist the etchant completely or,
where incised by lines, allow etching to occur unimpeded. But gelatin absorbs the
etchant and allows it to seep through to the copperplate. The thinner resist allows
etchant to seep through first and etch deepest ~ these areas correspond to the darkest
areas of the image. Thicker resist holds the etchant back longer, so that only light
etching occurs. By moving the plate through various etching baths, it is possible to
adjust how deeply each tone is etched in relation to other tones. The illustration shows
an enlarged cross-section of the copperplate ready for etching, with aquatint grain
(black dots) fused to the plate and the permeable gelatin resist (bright orange) above
that.
Pre-etch copperplate
How does the resist get thicker or thinner? Ultraviolet light (UV) sets off a chemical
reaction that hardens or crystallizes the gelatin. When exposed in contact with a
transparency, the highlights admit more UV, the shadows less, and this difference in
UV exposure causes different thicknesses in the gelatin.
Cross-linking of UV-exposed gel
The UV-exposed gelatin is adhered to the copperplate, allowed to set, then the
unexposed portion is washed off. The resist must dry in a perfectly even way to
prevent irregularities in the etching, though there is creative potential . The 'crater' in
the surface of one of the Potato Moons, for example, originated from a break in the
resist. And the flowing motion in the upper right of Westwind came from the actual
flow of an irregularly drying resist. I plan to explore such effects further in future.
After drying the resist and masking the plate to confine etching to the image area, etching is done in a
series of ferric chloride baths. The first and strongest etches only the shadows but does not penetrate
the thicker resist of the midtones and highlights. More dilute etchant, having more water, soaks through
the thicker resist and starts etching midtones and highlights in succession. If the resist has been overexposed, the etchant will never get through to the highlights. But highlight etching, when it occurs,
must be brief to retain the impression of sunlight, as in Ogatama-2, or clouds (Enoshima, Oze Path), or
snow (Three Friends, Gate of Zuisenji, Snow Country, other Snowscapes).
After etching, we take a proof and if OK, remove the resist and aquatint grain, and file and bevel the
edges of the plate to prepare it for printing on the etching press. Here is the etched copperplate from
which the Hokokuji print was made >
Etched plate, Hokokuji
The image is laterally reversed when printing. The dark areas of the copperplate, having been etched as
much as 20 or 30 times more deeply than the light areas, hold that much more ink and create superb
tonal variety in the print. For each impression, the plate is inked, wiped, and printed on the etching
press. This involves clearing the ink from the aquatint 'lands' and image highlights with gradually
decreasing wiping pressure. Finally a very light passage over the plate, known as retroussage, and the
plate is ready to roll through the press ~ always an exciting moment.
Etching papers differ in how they take the ink, how absorbent they are, tone, and
surface texture. I use harder, less absorbent papers such as Lana Gravure and Magnani
for lighter images of sand and snow. Deeply etched plates that transfer a lot of ink
print well on more absorbent papers such as Fabriano, Kyokushi, or Ganpi. The thinnest
Ganpi (middle illustration, front) can be attached to a heavier sheet during printing for
a unique gossamer effect. Shown below are some of my favorite etching papers and
Japanese washi >
PLATINUM PRINTMAKING MADE SIMPLE
By Gary Auerbach
As a serious amateur photographer for more than 20 years, it was only in 1989
after suffering a disabling wrist injury in my chiropractic practice, that I turned
my full attention to photography. Looking over my earlier work, I was
disillusioned that much of it was already showing signs of deterioration. Despite
using fiber-based papers, selenium toning, and proper storage, I realized that no
matter how good my photographs might be, I was working in a medium destined
to self-destruct.
I had read numerous articles on alternative methods of photographic
printmaking, searching for ways to make photographic images more archival.
One of the greatest collections of photography exists at the Center for Creative
Photography at the University of Arizona in Tucson. There I found platinum and
palladium images of early Steichen and Weston, and newer images by Dick
Arentz. I was hooked. Not only were these photographs magnificent, with a very
special soft, but sharp look, but they would stand the test of time.
I could appreciate that there was a new depth of image possible with the
platinotype, with the added benefits of true archival permanence. My readings
also led me to believe that the process seemed complicated and difficult. Yet I
have found that by adhering to several steps, platinum printmaking can be
relatively simple and very rewarding. The three basic components of platinum
printmaking are a shot glass, a platinum cocktail mixture, and "a little help from
heaven" - the sun.
Getting Started
I wanted to work in a full continuous tone black and white process, so I chose the
platinum/palladium method. Bostick & Sullivan offers a starter kit* of chemistry
which includes palladium chloride, and potassium chloroplatinite. To clear the
print, I use EDTA (a chelating agent to clear ferrous oxalate from the print).
Platinotypes are an iron process that uses ferric oxalate in combination with the
metal salts of platinum and palladium to create the image. So far so good. No
need for any acids to clear prints as in the old days, no more hypo, in fact, no
more darkrooms! This process can be done under a tungsten light. Since you
work on watercolor paper, no more photographic paper. I initially tried and still
like the Cranes platinotype and ecru paper available through B & S.
After the chemistry kit and paper, you will need a contact frame large enough to
hold your negative and paper in contact. The easiest light source to begin with is
the sun. If you live in the Southwest as I do, this is a fairly dependable source. If
you live in London or Seattle, an old GE sun lamp or facsimile will work just fine
for small format images.
The Negative
Platinotypes are a contact print process, meaning that your image is as large as
your negative. They also can print in a much wider density range than silver.
Search your negative drawers to find ones that look very dense. Almost
bulletproof. These are going to be the negatives that will print the best. I began
with a lot of 2 ¼ negatives for experimentation. You will be amazed how many 2
¼ platinum/palladium prints you can make with the starter chemistry set.
Contrast
The platinotype has a great control over contrast. But you must have a negative
that is not too thin. Many silver negatives that print on # 2 paper are too thin.
Two separate solutions of ferric oxalate will be mixed - the one that has chlorate
added to it will affect contrast.
There are essentially 13 different grades of contrast that can be used. Working
from negatives developed for silver printing, a number # 7 emulsion is a good
starting point.
EMULSION CONTRAST CHART
SOLUTION NO. SOLUTION A SOLUTION B SOLUTION C
#1
12
0
12
#2
11
1
12
#3
10
2
12
#4
9
3
12
#5
8
4
12
#6
7
5
12
#7
6
6
12
#8
5
7
12
#9
4
8
12
#10
3
9
12
#11
2
10
12
#12
1
11
12
#13
0
12
12
A+B=C
SOLUTION A= Ferric Oxalate
SOLUTION B=Ferric Oxalate with Chlorate
SOLUTION C= Platinum & Palladium
Making your Emulsion
A whiskey shot glass is just the right size for your drops. Using eyedroppers,
squeeze the specified number of drops of the two ferric oxalate (solution A and
B) solutions with the specified amount of platinum and palladium.
The drops of the metals (solution C) always equals the number of drops in
solutions A plus B. Within C, you can mix platinum and palladium however you
would like.( ie. all palladium, all platinum, or a mix of each). For reasons of cost
and affect, I use three or four palladium for each platinum. While platinum is
four times the cost of palladium, platinum gives more contrast than does
palladium. Palladium adds a warm tone and fine grain to the print. A small
quantity of platinum will give a deeper black to your image. If you use 24 drops
as in this formula, you will be able to hand coat an image about 5 x 7 inches in
size. If you are going to be doing 2 ¼ images, cut the formula in half.
The Coating Process
Prepare your paper to be coated by securing it with a few small pieces of
masking tape. Once the chemistry has been measured into the shot glass, swirl it,
then spill it quickly onto the paper. Spread the emulsion out evenly (using a foam
brush or non-metallic Hak brush) covering each area of the paper three or four
times. Mark the four edges of the area you want to coat with a tiny pencil mark.
Or you can use construction paper or rubylith to create a mask for a clean edge.
Many will overcoat the image size by one inch or so to show the negative edge.
Others will coat inside the negative edge to make the image float. The latter
conserves emulsion materials. Stop spreading once the emulsion becomes tacky.
Brushing more than necessary will cause streaks and abrade the surface of the
paper.
Dry your paper by putting it in a dark closet for a few hours, or use a hairdryer
on a warm setting to accelerate drying. To ensure that it is dry, take your hand,
while dry, and run it across the paper in all corners. A paper with moist
emulsion will ruin your negative. All platinum printers have lost at least one
negative this way, so take care on this last step.
Printing
Take the paper, put the negative on top of it (notches on the left for large format
shooters), put it into a contact frame with clean glass and seal it up. Using the
sun as a light source, take a meter reading of its value (for reference during your
printing times). As the value of your sunlight goes up, printing time in the sun
will shorten. As the value goes down, printing times will increase. Do a test strip
just as you would in silver printing. Clouds will definitely effect exposure and
contrast. Let's say you estimate a starting value for exposure in the sun at four
minutes (Tucson, Arizona sun) at 11:30 in the morning. I would test at one
minute intervals from three to six minutes. A slight latent image is visible after
exposure.
Developing
To develop is simple. Density of image is determined only by exposure, not by
development. Development will be visible instantly. Dam the developer
(ammonium citrate) to one end of an 8x10 tray, slip your print face up into the
base of the dam, and drop the tray to the level. This is a great thrill and the
moment of truth for much of your work. Leave the paper in the developer for 30
or 40 seconds. The developer becomes slightly toxic as it builds up with
platinum/palladium solids so rinse fingers after handling . Lift the paper out
with two hands, draining the developer off the sheet, and put in the clearing
agent (EDTA) for about five minutes. You will have two or three successive 8x10
trays of EDTA (non toxic) to remove the yellow stain out of the paper. Your last
tray should stay clear. After 15 minutes of EDTA clearing, wash with clear
water. Depending on the paper your use, fifteen minutes to one hour of washing
is sufficient.
After washing, lift the print with two hands (saturated paper is soft and will tear
easy) and put it on blotter paper or fiberglass screens to dry. This will vary by
region (Arizona is three or four hours). Or speed dry with a hair drier.
With the print in front of you, you will notice that the final density is slightly
darker than when it was wet on development. The details in the print will pop in
the last elements of drying as the paper stiffens up. Voila!
You can experiment with small format cameras by piecing three or four
exposures together so that you can make a larger image. If you don't have access
to an enlarged negative, make a good silver print of the smaller negative image
and have a blueprint house make you a high contrast enlarged negative for about
$15.
Good luck. I know that you will have great fun and success with this very
beautiful and permanent process.
A SOURCE FOR CHEMICALS
Bostick & Sullivan Starter Kit $110.
20 ml. palladium chloride
10 ml. potassium chloroplatinite
25 ml. of #1 ferric oxalate
25 ml. of #2 ferric oxalate with chlorate
1 qt. ammonium citrate
500 gm EDTA
5 sheets Cranes platinotype paper
5 sheets Cranes ecru paper
One foam brush
Bostick & Sullivan
P.O. Box 16639
Santa Fe, NM 85706-6639
Tel: 505 474 0890
Email richsul@roadrunner.com