April 23, 2014
BR: When Mrs. Brown gives you clay out of
the bag, what stage is it in?
EQ: What are the 6 Stages of Clay?
April 24, 2014
BR: What is the FIRST THING you do once
you have been given clay when working with it?
(ALWAYS!)
EQ: What are the 6 Steps of Using Clay?
April 28, 2014
BR:
What is the saying for applying two pieces of
clay together?
EQ:
What is the process of scoring and slipping?
April 29, 2014
BR:
What is slip?
EQ:
Is clay an additive or subtractive process?
April 30, 2014
BR:
What are some ways to decorate clay?
EQ:
What is applique?
May 5, 2014
BR:
What is a firing cycle? What is the length of a
firing cycle?
EQ:
What are the “wares” of clay?
TODAY
• Please follow along with the PowerPoint
and fill in your Ceramic worksheet.
• Daily grade given for being on task and
participating; if you are off task/sleeping
you will loose points and a possible
detention.
• You will be tested on this information and
it will also be on the final exam.
Bell Ringer
March 4, 2015
What is clay?
Comprehensive Art
Mrs. Brown
What is Clay?
Clay is . . .
. . .a fine mixture of decomposed
igneous rock materials and
organic matter.
• Clay is continuously
being formed.
Over time, exposure to the
elements cause the materials to
break down into smaller and
smaller pieces: Weathering
Boulders
Rocks
Pebbles
Fine grain = materials that
make up clay.
Weathering Processes:
Objects made from any
type of clay that is fired
with the aid of heat
History of Ceramics
• It is hypothesized
that ceramics came
about when humans
1st learned to control
fire.
• Old methods and
concepts are still
used today.
• Anthropologists use Stone Age
clues to piece together a variety
of possible theories of ceramic’s
origin
• Greece 1600 B.C
• Some jars as tall as 6 ft
• Created using the coil
method
Communication & Documentation:
Cuneiform Script
• Early system of
writing in
Mesopotamia
• Stylus pressed
into clay tablets
• Record-keeping
of laws,
historical
events, &
harvests
Cylinder Seal
Form of signature, or identification on
important documents.
Hunting Scene
2250-2150 BCE, Mesopotamia
• Pots were widely used
as funerary objects in
prehistoric burial
grounds
• Contained food to
accompany dead on
journey to the afterlife
• Infants and small
children
• Ceramic figurines and
animals to protect the
deceased.
Terracotta Warriors
• Form of funerary art - buried with the First
Emperor of Qin
(He was the first emperor of China in 221 BCE.)
• Their purpose was to help him rule in the afterlife.
• Architects are currently still excavating
6 Steps to Using Clay
1.
2.
3.
4.
5.
6.
Early Preparation (Levigation)
Forming Clay (5 major methods)
Drying Clay
Decorating Clay
Glazing
These two stages (5 & 6) can
happen in reverse order as well.
Firing
Step 1: Early Clay Preparation
• Early potters dug their raw material out of the
ground, and it often contained impurities such as
pebbles or plant matter.
• To remove these, potters would dry the clay in the
sun, crush it into smaller lumps, and pick out the
unwanted material.
• Then, they rehydrate the dry clay to make it
workable.
• This method was fine for making a few pots, but it
was difficult and time-consuming.
** The clay that Mrs. Brown gives you has already been
through this early clay preparation process.
Modern Clay Preparation
• Potters discovered it was much easier and
faster to separate impurities by adding water
to the clay and then pouring the liquid clay
(slip) from one container to another.
• This process is known as decanting.
Decanting causes the coarser materials to
settle on the bottom.
• Another traditional method for removing
impurities is known as Levigation.
The earliest and simplest methods are
still used today.
Four Basic Hand Building Techniques:
1.
2.
3.
4.
Pinch Method (oldest method)
Coil Method
Slab Method
Molding Method
Hand Building :
Process of forming pieces using hands
without the use of a potter’s wheel;
30,000 years old.
Pinch Method
• Is when clay is pulled and
pinched in order to shape an
object with fingers.
• It is the oldest form of ceramic
hand building.
Pinch Pot
Pinch
Method:
Two Pinch Pots Combined to
create a hollow form:
Coil Method
Created through long ropes/coils of
clay that are of equal thicknesses are
used to build a ceramic object
Coil
Coil
Slab Method
• A method of rolling out clay
flat to an equal thickness.
• Slabs can be cut into shapes
and used to construct ceramic
objects.
Slab Method
Slab Method
Throwing: A method of forming clay in which
the sculptor uses a pottery wheel.
Throwing is NOT a technique of hand-building.
Potter’s Wheel : A machine that
forms pottery using a wheel
Step 3: Drying Clay
• Potters must know how to control the rate at
which clay dries. Clay shrinks as it dries and,
if it shrinks too rapidly, it can crack.
• Clay that has dried to this point is in the
leather-hard stage; when pressure is applied
to the clay, the form will not easily distort.
• See the following Stages of Clay.
6 Stages of Clay
1. Slip
2. Wet/Plastic
Stages 2 – 4 are
also known as
3. Leatherhard
Greenware.
4. Bone-Dry
~Firing~
5. Bisque (Bisqueware)
~Firing~
6. Glazeware (Glazenware)
6 Stages of Clay
1. Slip: Liquid clay; “glue”
required to attach two pieces
of clay together.
6 Stages of Clay Con’t
2. Wet: Plastic clay;
workable; easily manipulated.
** IDEAL
* When Mrs. Brown gives you clay
out of the bag it is in this stage.
6 Stages of Clay Con’t
3. Leather Hard: Clay is stiff but still
damp; firm -maintains form and can
be smoothed, carved, and added to.
*not easily
distorted,
but can still be
carved.
6 Stages of
Clay
Con’t:
4. Bone-dry: Water has evaporated
from the clay; form is brittle and
ready to be fired.
** Clay becomes lighter in color
6 Stages of Clay Con’t
5. Bisque (Bisqueware): fired
once; ready to be glazed then
fired a second time.
6 Stages of Clay Con’t
6. Glazeware: Objects that
have been fired a second
time after glaze has been
applied.
R*E*C*Y*C*L*E :
Clay may be recycled through the Bone
Dry stage by simply rehydrating it.
**Once clay has been fired it becomes permanent
– it can no longer be recycled.
Step 4: Decorating Clay
• Impressing uses an object to press or
stamp a design into the clay.
• Combing marks the surface of the clay
with uniform lines.
• Burnishing involves rubbing and
polishing the surface with a smooth
stone or piece of hard wood.
Incising – Carving or cutting into
the clay surface with a tool.
Step 5: Glazing
• Glaze: A coating of liquid
glass that is applied to a clay
surface that melts together
and forms a decorative and
protective surface.
Glaze also makes your ceramic
piece:
• Colorful
• Food Safe (check glaze label.)
• Water Proof
Step 6: Firing
The earliest pottery was fired in open fires.
Firing Methods
The main methods of firing clay are:
Open Firing: in which the vessels and
fuels are set together.
Kiln Firing: in which the vessels and
fuels are separated.
The Kiln:
• Chamber for firing
your clay.
• Clay MUST be Bone
Dry to fire.
• You must fire your
clay for it to become
permanent.
Kiln (Con’t)
• A kiln can reach
temperatures of
2,500 degrees F
and higher.
• Your oven at home
possibly reaches
500 degrees - at the
most.
The Kiln
8-12 hours = to heat to
maximum temperature.
+ 8-12 hours = to cool
16-24 hours for firing cycle.
** That’s why it takes longer to get your Ceramics
projects back.
What are the
3 Variables of Clay?
1.Plasticity
2.Moisture
3.Heat
Plasticity:
• Workability
• Is the quality of clay that allows it
to be easily manipulated and still
maintain its shape.
• Ideal texture for clay = similar to
play-dough
• The ability to hold
together while being
shaped (workability)
Create the Coil
- Does it stretch and bend
without breaking?
Plastic
- Test It! Wrap a coil around
your finger. If it cracks, the
clay is not plastic.
Not Plastic
Moisture
•
•
•
•
All clay contains water.
Clay dehydrates when exposed to air.
Add water to clay to make it more plastic.
Too little or too much water causes clay to
become less plastic.
Tip: Mist clay with damp sponge. ALWAYS
wrap your projects with plastic (and/or a
wet cloth) before storing.
Heat
Fire or heat makes the shape permanent and
returns the clay to its rocklike state.
• Firing at temperatures ranging between
500 - 800 degrees Fahrenheit changes the
physical state of clay mineral crystals into a
hard, stable medium.
• When clays are heated above these
minimum temperatures, they become
ceramics.
Other Ceramics & Clay
Vocabulary To Know:
Kneading:
• Process of pushing clay together.
Wedging:
• Process of slamming, kneading,
or pushing clay together.
1.
2.
3.
4.
Removes air bubbles trapped in the clay.
Equalizes moisture.
Makes clay texture uniform.
Re –forms smaller pieces into one big
one.
**You MUST ALWAYS wedge/knead
first BEFORE using your clay.
Score:
• Means the process of roughing up the
edges of clay with a tool in order to
join two pieces of clay together.
You must always:
“score, slip, and press” when
joining any two pieces of clay
together.
Functional = pottery that serves a
purpose or does a job.
Examples include:
dishes, vases,bowls,
cups or plates.
Aesthetics:
• The visual beauty or pleasurable qualities
of an object.
Sculpture in the Round:
•
A freestanding sculpture
that is meant to be seen
from all sides.
Chris Gustin
Golden Rules of Ceramics:
• Always WEDGE/KNEAD clay first.
• Score, slip, and press ALWAYS
when joining two pieces of clay.
• No trapped air! – poke escape hole!
• Clay must be no thicker than the tip
of your thumb.
• Always cover clay fully so that it will
not dry out.