Understanding Fabric

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Pre-Costuming
Understanding Fabric
Maîtresse Irène leNoir
irene@chezirene.com
© 1999-2009 Jessica I. Clark
Permission to print a copy for your own use freely given. Please contact me for permission to reprint or distribute.
In order to properly understand fabric, you need to understand how it’s created. That means
understanding where the fibers that make up the fabric come from, how they’re turned into
fabric, how the fabric may be colored, and how the fabric may be treated or decorated.
Fiber Content
The basic building blocks for all fabrics are fibers. Although the number of different fibers is
quite large, they can all be categorized as either natural or manufactured. The natural fibers can
then be further divided into plant or animal fibers, and the manufactured into synthetic and
cellulosic. (The term synthetic is also commonly mis-used to refer to all manufactured fibers.)
Synthetic fibers are composed of chemical compounds derived from petroleum or natural gas.
Cellulosic fibers are derived from cellulose, a natural fiber. Because of this natural source for
the raw material, many people mistakenly believe that cellulosic fibers are natural fibers.
However, chemical processes are used during the manufacture of cellulosic fibers that dissolve,
refine, and reconstitute the cellulose. In the process, the cellulose is often weakened or even
partially replaced with synthetic compounds.
Some common fibers and their derivations follow.
Fiber
Acetate
Acrylic
Angora
Cotton
Hemp
Linen
Lyocell
Nylon
Olefin
Polyester
Ramie
Rayon
Silk
Spandex
Vinyl
Wool
Category
Cellulosic
Synthetic
Animal
Plant
Plant
Plant
Cellulosic
Synthetic
Synthetic
Synthetic
Plant
Cellulosic
Animal
Synthetic
Synthetic
Animal
Derivation
Cellulose modified with acids
Long-chain synthetic polymers composed of acrylonitrile units
Hair of the angora goat or angora rabbit
Seed hairs of the cotton plant
Stem of the hemp plant
Stem of the flax plant
Cellulose modified without synthetic replacement
Long-chain polymeric amides
Polymers composed of ethylene, propylene, or other olefin units
Resin formed of polyhydric alcohols and dibasic acids
Stem of the ramie plant
Cellulose modified with some synthetic replacement
Silkworm cocoons
Polymers of polyurethane
Polymerized vinyl compounds
Hair of sheep or other animals
Aside from the classification as to their source, fibers can also be classified as either filament
fibers or staple fibers. Filament fibers are those that are extruded to an indefinite length. While
most filament fibers are manufactured, silk is an example of one that's naturally occurring.
Staple fibers, by contrast, have set lengths. Staple fibers can occur naturally, or they can be
produced by cutting a filament fiber into shorter lengths. Sometimes the comparative terms of
long or short are used to describe the staple length of a given fiber in comparison to others of the
same type. As an example, Egyptian cotton comes from a variety of cotton that has a longer
staple length than most cottons.
© 1999-2009 Jessica I. Clark
Understanding Fabric - Page 1
Different fibers have different properties. Natural fibers breathe, and are therefore usually cool
in warm weather and warm in cold weather. In contrast, synthetics don’t breathe well. So they
aren’t very comfortable in warm weather. Cellulosic fibers breathe better than synthetics, but
usually not as well as natural fibers. Cotton is absorbent. Linen is extremely durable. Polyester
is resistant to wrinkles. Silk has a high tensile strength and resists abrasion. Spandex is highly
elastic. Vinyl is waterproof. Wool retains warmth even when wet, and tends to cease burning
when removed from a source of flame. But these are just a few examples that only skim the
surface. A complete listing of the properties of these and other fibers could fill a book.
Different fibers have different innate care requirements. Unfortunately there's no way to
definitively state which methods can be used for which fabrics, as too many variables can affect
the type of care the fabric will require. However, a few generalizations can be made. One is that
all natural fibers can be washed. They may need to be washed in cold water or by hand, but they
can be washed. Another is that very few fabrics truly need to be dry-cleaned. They can often be
hand-washed or machine-washed on a delicate cycle instead. If you’re ever in doubt about how
to care for a fabric, wash (or otherwise clean) a test swatch first to see how it behaves.
Yarns
Although not always necessary, most methods of fabric construction require the fiber to first be
formed into a yarn. But note that when speaking about fabric construction, a yarn doesn’t need
to be as thick as we usually think of when we think of yarn. A “yarn” can actually be as thin as
what we would normally consider thread.
To form a staple yarn, staple fibers are first carded (combed) to align the fibers. At this point
noils (shorter or tangled staple fibers) are sometimes also removed. Once carded, the fibers are
spun (twisted) together to form a yarn. Filament yarns are formed from filament fibers gathered
together and laid parallel along their lengths. These fibers can then be spun, but don’t need to
be. Some yarns are monofilament, or formed from a single filament fiber. Yarns can also be
formed from filament fibers spun together with staple fibers. Two or more spun lengths can also
be plied (twisted together) to add strength, bulk, or for appearance. A yarn formed in this
manner is referred to as a two-ply yarn, three-ply yarn, etc.
Although not yarns in the strict sense of the word, sometimes you’ll encounter fabrics created
from what could be referred to as unspun yarns. In these cases, carded staple fibers aren’t spun
together, but are instead just aligned into a long, thin yarn shape. But without the twist to hold
the fibers together, these unspun yarns are very weak and pull apart easily.
Sometimes yarns are spun with slubs (irregular thickened spots) along their length. These slubs
can be an accidental defect. But they’re often deliberately included to give the yarn texture. As
an example, noils that were removed in the carding process can be spun either by themselves or
added to longer staple fibers to produce noil yarn. Other decorative yarns can be created by
combining plies of different fibers or colors. In addition, plies spun with different tensions can
be combined to create textured yarns.
© 1999-2009 Jessica I. Clark
Understanding Fabric - Page 2
Woven Fabrics
Probably the most common type, woven fabrics are created from the intersection of two sets of
yarns. The yarns running the length of the fabric, the warp, are placed parallel to each other
along the length of a loom. Then the weft yarn is passed over and under the warp, perpendicular
to the warp, forming the fabric as it moves back and forth.
Woven fabric has a grain. That is to say, the yarns are aligned in a certain direction and pieces of
fabric cut at different angles across the grain will behave differently. The lengthwise grain of the
fabric, sometimes simply referred to as the grain, runs in the direction of the warp yarns. The
crosswise grain runs in the direction of the weft yarns. Any angle not in line with the lengthwise
or crosswise grains is referred to as bias. The true bias of a fabric is the forty-five degree angle
between the lengthwise and crosswise grains. Unless a fabric is woven with an elastic fiber, it
won’t stretch along its lengthwise or crosswise grain. But it will stretch along the bias. Another
characteristic of woven fabrics is they have a tendency to fray (come unwoven) along cut edges.
While it’s usually necessary to take steps to prevent woven fabrics from fraying, some fabrics are
less prone to fraying in general, and most fabrics are less prone to fraying when cut on the bias.
There are many different patterns in which fabric can be woven, and many of these have names.
An evenweave, also called a plain weave or a tabby weave, is the most basic weave. In this
weave, the weft yarns pass over one warp yarn and under the next. A basketweave is similar to
an evenweave, but with groups of two or more yarns being treated as one. A rib weave is
characterized by prominent ribs in the weft. These can be created by using larger yarns in the
weft than are used in the warp, by using two or more yarns in the place of one weft yarn, or by
using many more yarns in the warp than in the weft.
A twill weave is characterized by diagonal lines across the surface of the fabric. A warp-faced
twill (or simply twill) is formed when each warp yarn floats (passes) over two or three weft yarns
before passing back under, with the spacing of the floats arranged to produce the diagonal lines.
A weft-faced twill is one in which the weft yarns float across the warp. An even-faced twill is
one in which the warp (or weft) yarns pass over and under an equal number of yarns. While
there are many patterns and designs that can be created using variations of twill weave, some are
distinct enough they have specific names. Herringbone twill is a variant in which the floats are
arranged so as to produce zig-zag lines. Diamond twill is one in which the floats are arranged to
form repeating diamond motifs. Houndstooth is a variant in which the floats and stripes of color
in the warp and weft are arranged to form an allover design of barbed or broken squares. Twills
can also be described numerically. As examples, a 3:1 twill is one in which the yarns float
across three yarns before passing under one, while a 2:2 twill is one in which the yarns float
across two yarns before passing under two.
A satin weave is similar to a twill, in that yarns float across the surface. However, a satin is one
in which the floats pass over 4 or more yarns. Additionally, the floats are arranged so as not to
create any obvious diagonal lines, but instead just a smooth surface. A sateen is a weft-faced
satin.
Seersucker is a fabric woven with warp yarns of different tensions. These different tensions
cause lengthwise puckered stripes to develop once the fabric is released from the loom. Piqué is
© 1999-2009 Jessica I. Clark
Understanding Fabric - Page 3
a fabric which can be somewhat similar in appearance to seersucker, with lengthwise and/or
crosswise puckered ribs or figures. These puckered effects are created by interlacing dual warps.
Pile fabrics have a raised surface of loops or sheared loops. Velvet is created by weaving a
fabric with supplementary warp yarns which are drawn out and looped, and then sheared off,
leaving a pile on the surface of the fabric. Alternately, it can be created by weaving two lengths
of fabric with the supplemental warp passing between them, and then cutting the two fabrics
apart. Velveteen is a fabric similar to velvet, but created with a supplementary weft. Corduroy
is a style of pile fabric in which the pile has been cut or woven in stripes, called cords or wales,
running the length of the fabric. Terrycloth has a pile of loops.
A jacquard is a fabric woven on a jacquard loom. This type of loom differs from standard looms
in that rather than controlling the warp yarns in groups, each warp yarn is individually
controlled, allowing a much greater capacity for complex designs. A brocade is a fabric
characterized by highly complex, often multi-colored designs created by using supplemental weft
yarns, which intermittently float across the back of the fabric. A damask is a fabric formed from
satin and sateen weaves, used to create reversible figured designs. A tapestry is a completely
weft-faced fabric, often characterized by weft yarns that don’t pass the full width of the fabric,
but instead fill smaller areas.
Another style of figured weave is a dobby weave, produced on a loom with a dobby attachment.
This attachment resembles a jacquard loom, and is used for weaving small motifs over a small
number of yarns. Swivel weaves are made on looms with attachments for guiding additional
weft yarns over limited areas.
Leno weave fabrics are a variety of weave in which pairs of warp yarns cross over each other,
locking the weft yarn in place. Double weaves are woven from two distinct warp and weft sets
connected at intervals by the warp and/or weft of one passing through the other.
Fabrics can also be woven with many other varieties of designs that have no specific names.
Knit Fabrics
The second most common type, knit fabrics are created by looping a yarn through itself. These
loops, called stitches, are arranged in courses (rows across the width of the fabric) and wales
(columns along the length of the fabric.) Traditionally, this was accomplished by hand with
knitting needles, forming one stitch at a time. For modern mass production though, complex
knitting machines are used that form an entire course of stitches in one pass. Although these
methods for producing knits differ, they create fabrics that are structurally identical.
Knit fabrics also have grain and bias. The stitches forming the fabric are oriented in a certain
direction, and the fabric will behave differently at different angles across its grain. Unlike
wovens, knits will stretch in any direction, though usually more so across the width of the fabric
than along the length. Still, this property can be controlled through deliberate choices of yarn
and tension. As a result, knits can be created that are stable (relatively stretch-free) or that
stretch equally in any direction. Knit fabrics won’t fray the way wovens will, but they can
unravel or run. Cut edges unravel as the stitches making up the knit fabric unloop themselves
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along the length of the cut. Runs occur as wales of stitches unloop themselves in a chainreaction originating at a single broken yarn in the knit, and traveling up and down the length of
the fabric from this initial break.
As with wovens, there are many different patterns in which fabric can be knit. A plain knit, or
stockinette, is the simplest, and has the appearance of interlocking V-shapes on the front and
interlocking crescent shapes on the back. If the direction of the stitches is reversed the V-shapes
occur on the back and the crescent shapes on the front, forming a purl knit. Rib knits are created
by alternating wales, or sets of wales, of knit and purl stitches. Velour is similar to velvet or
velveteen, but with a knit fabric for the base. Fake fur is usually manufactured as a pile fabric
with a knit base.
There are also a wide variety of decorative patterns that can be created by alternating knit and
purl stitches in certain sequences and/or repositioning stitches within a course. Perhaps the most
common of these patterned knits are cable-knits, in which stitches are repositioned to create the
effect of twisting ropes or cables.
A double knit, similar to a double weave, is knitted with two sets of needles, producing a double
thickness of fabric, with the layers joined by interlocking stitches.
Other Fabrics
Felt is a type of fabric composed of irregularly oriented fibers which have been interlocked and
formed into a sheet. This interlocking of the fibers is achieved through a combination of heat,
moisture, and agitation. Not all fibers can be felted. In order for felting to be possible, the fibers
need to have microscopic barbs along their length. During the felting process, these barbs grab
hold of each other and interlock. Wool and certain synthetic fibers have these necessary barbs.
Unlike wovens and knits, felt doesn’t have grain, as the fibers making up felt aren’t oriented in
any specific direction. Because of this, felt won’t fray when cut and it also tends to be waterresistant. Felt will usually stretch, but only to a point. After that point, continuing to attempt to
stretch the felt will simply begin to pull the fibers apart. Felt can also be shaped by using a
combination of heat and moisture.
There are still many other methods of fabric construction, some moderately common and some
very obscure. Crochet is a technique similar to knitting in that it loops a continuous length of
yarn through itself. However, crochet is performed with a single hook. Additionally, unlike
knitting, crochet can't be mechanized. Netting is a process in which a length of yarn is looped
and knotted to itself in an open pattern. Naalbinding is an obscure historic technique in which a
continuous length of yarn is stitched to itself in interlocking loops. Sprang, another historic
technique, involves crossing and twisting parallel yarns to produce a fabric that looks like a cross
between knitting and netting. Macramé fabrics are formed by knotting yarns together in
complex patterns. Lace is produced through a wide variety of techniques. Barkcloth is produced
by hammering the bark of certain species of trees into a thin sheet. A variety of non-woven
fabrics are created through varied techniques ranging from extrusion to felt-like processes.
Leather, suede, and fur, while not really fabrics, can in all other respects still be treated as such.
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Understanding Fabric - Page 5
Other Terminology
Selvedges are the two long finished edges of the fabric, formed as the fabric is woven, knit, or
otherwise created. Threadcount is a measure of how many threads per inch are found in a woven
fabric. Gauge is a measure of how many stitches per inch are found in a knit fabric. It’s worth
noting that for threadcount figures to give a truly accurate description, they must be given for
both warp and weft, as they need not be the same. Similarly, gauge should specify stitches
vertically and horizontally.
It’s also worth noting that fabrics with a low threadcount or which have been loosely woven tend
to shrink more than higher threadcount or more tightly woven fabrics of the same fiber content.
This effect also occurs with lower gauge or looser knits.
Drape is a word used to qualitatively describe how a fabric behaves when allowed to fall against
itself or in folds. As an example, twills drape better than evenweaves. Body is a similar word
used to describe how firm a fabric is. As an example, velveteen has more body than velour.
Nap is a word used to describe any soft, fuzzy surface such as those found on flannel or pile
fabrics. It’s also often used to indicate a fabric which has a directional nap, such as velvet, or the
direction of the nap.
Blends
Not all fabrics are composed of just one fiber. Often, different fibers are blended together for
any of a variety of reasons. Factors that can influence the reasons for creating the blend may
include cost, durability, availability, and how readily the fabric accepts dye.
There are several ways in which different fibers can be combined. The most basic is for the
fibers to be mixed before the yarn is spun. Yarns can also be composed of plies of different fiber
contents. Another variation is to spin the yarn with a core of one fiber and an outer wrapping of
another. The fibers can also be combined by using yarns of different content when creating the
fabric, such as using a warp of one fiber and a weft of another. Combinations of these methods
can also be used.
Coloring
The simplest form of coloring fabric is to dye it a solid color. But there are many different ways
of doing so. The most basic process is to dye the raw material, known as stock dyeing. One of
the advantages of dying raw fiber stock is that different colors or shades can then be spun
together to create complex yarns. For synthetics, pigment can be added to the chemical solution
before the fiber is created. This process is known as solution dying, and has the advantage of
being extremely colorfast.
The next point in the fabric manufacturing process at which color could be added would be after
the fibers have been spun into yarn. This is known as yarn dyeing. Yarn dyeing allows fabric to
be created from yarns of different color, allowing the possibilities of plaids, brocades, and other
woven-in designs. Space dyeing, a variation of yarn dyeing, is a technique in which yarns are
dyed at intervals along their length.
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Once the fabric has been created it can be dyed as whole cloth, which is known as piece dyeing.
The process of submersing cloth in a dye solution is referred to as vat dying. But not all solid
color fabrics are dyed in this fashion. Sometimes surface dying is used instead. In this process
the fabric is essentially painted on both sides with the dye. Surface dying is commonly used
because of its cost-effectiveness, and usually there's no discernable difference from vat dyed
fabrics. But sometimes during the surface dyeing process the fabric wrinkles or something gets
caught between the fabric and the source of the dye. As a result, the dye isn’t evenly applied
over the entire surface, leaving undyed areas. Because of this potential, you should be careful
when dealing with surface dyed fabrics, and watch for any flaws as your fabric is being
measured out.
Over dyeing, also known as top dyeing, is a simple variation of vat dyeing in which the fabric is
dyed in one dyebath, and then again (or multiple times) in the same or another dyebath. Over
dyeing can be used to build up deeper or richer tones of a color, or to combine different colors or
dye properties. Cross dyeing is another variation of vat dyeing in which cloth composed of
varying fiber contents is dyed. Because the different fibers accept the dye to different degrees,
the fabric doesn’t emerge from the dye bath as a solid color, but instead with different colors in
the areas of different fiber content. Even more complex color combinations can be achieved by
combining over dyeing with cross dyeing.
Other than applying solid colors, there are a variety of other coloring techniques. By far the
most common is printing, which includes the techniques of block printing, roller printing, and
screen printing (also known as silk-screening.) Simple to complex designs can be printed onto
the surface of the fabric, using any number of different colors. Fabrics can also be hand-painted,
again with any number of colors.
Resist dyeing is a method in which portions of the fabric are blocked out with a dye-resisting
agent or process before the piece is dyed. Complex designs can be created by repeating the resist
dyeing process, building up multiple layers of color. There are a variety of methods of resist
dyeing, most differing in the type of resist. Batik uses melted wax. Tie dying, a process familiar
to most, relies on compressing the fabric with lengths of string. Shibori is a category of Japanese
techniques in which folds, pleats, tied string, and/or stitches are used to compress the fabric. Ikat
is a complex technique in which the warp yarns of a fabric are painted and/or resist dyed before
the weft yarns are woven in. Dyes can also be resisted using other techniques without specific
names.
Once colors have been added in any of the above fashions, they can also be removed. Selective
application of bleach or other color removers can create interesting color effects, particularly
when the color removal process is halted before complete. Interesting effects can also be created
by applying the removing agent with a paintbrush, with a sprayer, over stencils or shaped
objects, or when used in combination with constriction techniques similar to tie-dyeing or
shibori. It’s worth noting however that not all dyes react the same to any given color remover.
Some may be easily removed and others may be resistant.
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Treatments and Decorations
Most fabrics are given finishing treatments during their manufacture to create special effects or
to impart specific properties. By far the most common treatment is to apply sizing, a glue-like
stiffening substance. Sometimes sizing is added to aid in some part of the production of the
fabric, but more often it’s added to alter the appearance and texture of the fabric, in an attempt to
make the fabric more marketable or appealing to the consumer. Sometimes a fabric is treated
with a glaze, a shinier and more permanent variety of sizing. Whereas many sizings are expected
to wash out, a glaze is intended to be an integral part of the finished effect of the fabric.
Some fabrics have physical processes performed on them to affect their appearance or texture.
Beetling is a process in which a fabric is hammered to produce a lustrous finish. Calendering is
a process in which fabric is passed through heated rollers under high pressure, producing a
smooth or glossy finish.
Flannels are created by brushing the surface of a woven fabric. As the fabric is brushed, fiber
ends pull loose from the yarns and form a fuzzy surface. Silvercloth is a particular variety of
flannel which has been impregnated with microscopic silver particles. It’s used to construct and
line cases for storing silver, as it impedes the tarnishing process. Fleece is created using the
same process as for creating flannel, but applied to a knit fabric.
Sometimes similar in appearance to flannel or fleece, fulled fabrics are created using the same
processes used to create felt. But rather than applying these processes to loose fibers, they’re
applied to a finished fabric. The fabric maintains the structure of its weave or knit, but becomes
stiffer and thicker and takes on some of the properties of felt, becoming more water-resistant and
fray-resistant.
Sandwashing is a process in which a fabric is washed with sand. The sand abrades against the
fabric in the washing process, softening it and imparting an irregular aged or distressed effect.
Stonewashing is a similar process in which pumice stones are used in place of the sand.
Heat or chemicals can be used to alter the surface texture or appearance of fabric. Designs can
be embossed into the surface, usually on velvets or satins. Caustic chemicals can be applied in
patterns to the surface of the fabric. These can cause the fabric to shrink unevenly, producing
puckered fabrics such as plissé. Alternately, the chemicals can be used to selectively remove, or
burn out, certain areas of the fabric. Devoré velvet is an example of a fabric created in this
manner.
Decoration can be applied to the surface of the fabric. Embroidery can add a variety of designs,
and may incorporate yarns of varying texture, thickness, or color. It can also be combined with
cutwork, producing fabrics like eyelet lace. Beads or sequins can be sewn or glued to the surface
of the fabric. Flock (loose fibers) can also be glued to the fabric in designs or over large areas.
Tufting is a process in which lengths of yarn are punched through the surface of the fabric,
creating a pile.
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Named Fabrics and Classes of Fabrics
In addition to the names for the many different types of weaves and knits, there are many words
for types of fabric. Sometimes these names precisely specify a fiber content and method of
construction. One example is denim, which is a cotton twill. Other times the name may only
define a category of fabrics with some common property. An example of this type of name is
gauze. While gauze is a lightweight, sheer, loosely woven fabric, it can be made from almost
any fiber.
When dealing with named fabrics it’s important to remember the goal isn’t to be able to name a
given fabric. That would be relatively pointless, and often not even possible, as the definitions
overlap so much that many fabrics could be called by several different names. Instead, the goal
is to be able to understand what type of fabric is meant when a named fabric term is used. For
definitions of more named fabrics, refer to the Glossary of Fabric Terms.
Once you understand the differences between the above aspects of fabrics and begin to gain
personal experience with them you’ll understand how any given fabric will behave, how durable
it will be, how it must be cared for, and what it will be like to work with. This knowledge will
then allow you to choose the right fabrics for your projects.
© 1999-2009 Jessica I. Clark
Understanding Fabric - Page 9
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