Saturday, September 3, 2016

Similarities and Differences in Woven Fabrics
Art Resource

Marie-Therese Wisniowski

Preamble
This is the fifty-sixth post in the "Art Resource" series, specifically aimed to construct an appropriate knowledge base in order to develop an artistic voice in ArtCloth.

Other posts in this series are:
Glossary of Terms
Units Used in Dyeing and Printing of Fabrics
Occupational, Health & Safety
A Brief History of Color
The Nature of Color
Psychology of Color
Color Schemes
The Naming of Colors
The Munsell Color Classification System
Methuen Color Index and Classification System
The CIE System
Pantone - A Modern Color Classification System
Optical Properties of Fiber Materials
General Properties of Fiber Polymers and Fibers - Part I
General Properties of Fiber Polymers and Fibers - Part II
General Properties of Fiber Polymers and Fibers - Part III
General Properties of Fiber Polymers and Fibers - Part IV
General Properties of Fiber Polymers and Fibers - Part V
Protein Fibers - Wool
Protein Fibers - Speciality Hair Fibers
Protein Fibers - Silk
Protein Fibers - Wool versus Silk
Timelines of Fabrics, Dyes and Other Stuff
Cellulosic Fibers (Natural) - Cotton
Cellulosic Fibers (Natural) - Linen
Other Natural Cellulosic Fibers
General Overview of Man-Made Fibers
Man-Made Cellulosic Fibers - Viscose
Man-Made Cellulosic Fibers - Esters
Man-Made Synthetic Fibers - Nylon
Man-Made Synthetic Fibers - Polyester
Man-Made Synthetic Fibers - Acrylic and Modacrylic
Man-Made Synthetic Fibers - Olefins
Man-Made Synthetic Fibers - Elastomers
Man-Made Synthetic Fibers - Mineral Fibers
Man Made Fibers - Other Textile Fibers
Fiber Blends
From Fiber to Yarn: Overview - Part I
From Fiber to Yarn: Overview - Part II
Melt-Spun Fibers
Characteristics of Filament Yarn
Yarn Classification
Direct Spun Yarns
Textured Filament Yarns
Fabric Construction - Felt
Fabric Construction - Nonwoven fabrics
A Fashion Data Base
Fabric Construction - Leather
Fabric Construction - Films
Glossary of Colors, Dyes, Inks, Pigments and Resins
Fabric Construction – Foams and Poromeric Material
Knitting
Hosiery
Glossary of Fabrics, Fibers, Finishes, Garments and Yarns
Weaving and the Loom
Similarities and Differences in Woven Fabrics
The Three Basic Weaves - Plain Weave (Part I)
The Three Basic Weaves - Plain Weave (Part II)
The Three Basic Weaves - Twill Weave
The Three Basic Weaves - Satin Weave
Figured Weaves - Leno Weave
Figured Weaves – Piqué Weave
Figured Fabrics
Glossary of Art, Artists, Art Motifs and Art Movements
Crêpe Fabrics
Crêpe Effect Fabrics
Pile Fabrics - General
Woven Pile Fabrics

The Glossary of Terms, Timelines of Fabrics, Dyes and Other Stuff, A Fashion Data Base, Glossary of Colors, Dyes, Inks, Pigments and Resins, Glossary of Fabrics, Fibers, Finishes, Garments and Yarns and Glossary of Art, Artists, Art Motifs and Art Movements have been updated in order to better inform your art practice.

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Introduction
Woven fabrics are similar in structure but differ in handle, drape and appearance depending of a number of factors. Today post focuses of similarities and differences of woven fabrics.

Tropical floral (Hawaiian) woven dress.


Similarities of Woven Fabrics
The width of the loom determines the width of the fabric. Hand-woven fabrics are usually 27 to 36 inches wide. Before the 1950s machine woven cottons were traditionally 36 inches wide. However, wider fabrics are more economical to weave and the garment cutter can lay out patterns to better advantage. New looms weave cotton 45 inches wide. Wool fabrics are 54 to 60 inches wide and silk type fabrics are 40 to 45 inches wide.

A modern Rapier loom.

The arrangement of warp and filling (weft) yarns is always at right angles to one another, a yarn position that gives the cloth more firmness and rigidity than the yarn arrangement in knits, braids and laces. Yarns can be raveled from adjacent sides of the fabrics. Yarn position also indicates the grain of the fabric.

Fishtail braid.

The warp and filling yarns differ because of the performance requirements of the loom and because they serve different functions in the fabric. The warp yarns (ends) usually have more twist and are made of better quality fibers because they must resist the high tensions put on them by the loom and because of the abrasion of the shuttle as it flies back and forth.

Two neighboring ends will resist the tearing force together resulting in higher tearing strength in warp direction.

It is very important to recognize the warp and filling directions of a fabric because:
(i) The fabric is stronger in the warp direction and it usually stretches least in this direction.
(ii) Fabrics are often stiffer in the warp direction because warp yarns have more twist. Therefore, the warp and filling drape differently.
(iii) The fabric will shrink more in the warp direction. The picture of the bias slip (see below) shows the differences between warp and filling shrinkage.

Shrinkage in crêpe slips. The warp shrunk more than the filling.

It is difficult to recognize a difference in the warp and filling directions of plain woven fabrics, but a trained eye can see the difference. Except for the first method given here, no one method fits all fabrics. Some of the methods given will be easier to understand as fabrics are studied, so reference should be made to the list given below.
(i) The selvage always runs in the warp direction (lengthwise) of the fabric.
(ii) Most fabrics stretch less in the warp direction.
(iii) Warp yarns usually appear straighter in the fabric. This is the result of tension on the yarns during weaving.
(iv) Warp yarns are usually regular yarns, while filling yarns may be decorative or functional yarns. (Regular yarns are the ordinary weaving yarns of medium size and medium twist and of uniform construction. Example: the yarns in percale fabric).
(v) Many fabrics have certain characteristics that indicate the warp and filling direction. For example, poplin always has a filling rib, satin always has warp floats and flat crêpe yarns in the filling and low-twist yarns in the warp.

Poplin - a fabric made using a rib variation of the plain weave. The construction is characterized by having a slight ridge effect in one direction, usually the filling. Poplin used to be associated with casual clothing, but as the "world of work" has become more relaxed, this fabric has developed into a staple of men's wardrobes, being used frequently in casual trousers.

All woven fabrics have grain and selvages. Grain is the term used in sewing to indicate the warp and filling yarns of the fabric. Lengthwise grain is any position along a warp yarn and crosswise grain is any position along a filling yarn. True bias is the diagonal of a square and garment bias is any position on the cloth between true bias and either lengthwise or crosswise grain. The diagram below shows why a garment bias edge will ravel more than any of the others.

Grain position of cut edges: (i) garment bias; (ii) true bias.

A selvage (selvedge) is the self-edge of a fabric formed by the filling yarn when it turns to go back across the fabric. The conventional loom makes the same kind of selvage on both sides of the fabric but the new shuttleless looms have different selvages because the filling yarn is cut and the cut ends are tucked back in by a special leno shedding mechanism. In some fabrics stronger yarns or a basket weave arrangement are used.

Definition of selvage.

Definition of fabric selvage or selvedges. In yard goods, the outer edges are constructed so they will not ravel. These finished edges are called the selvages (self-edges) and are often made with heavier and more closely spaced warp yarns than are used in the rest of the fabric by using more or stronger warp yarns or by using a stronger weave.

Plain selvages are similar to the rest of the fabric. They do not shrink and can be used for seam edges in garment construction. Tape selvages are made of larger and/or ply yarns to give strength. They are wider than the plain selvage and may be of basket weave for flatness. An example is the selvage on sheets. Split selvages are used when narrow items such as towels are made by weaving two or more side by side and cutting them apart after weaving. The cut edges are finished by a machine chain stitch or a hem. Fused selvages are the heat-sealed edges of ribbon or tricot yard goods made from wide fabric and cut into narrower widths.

Different types of selvages.


Differences in Woven Fabrics
Woven fabrics differ from one another in the pattern of interlacing – identified by weave names, such as plain, twill, satin – the thread count and balance. Specific woven fabrics within one weave group differ because of fiber content, yarn structure and fabric finish.

The basic twill pattern.

Thread or cloth count is the number of warp and filling per square inch of grey goods (fabric as it comes from the loom). This may be changed by shrinkage during dyeing and finishing. Thread count is written with the warp number first, for example, 80 x 76; or it may be written as the total of the two, as 156. (Thread count should not be confused with yarn count or number, which is a measure of yarn size).

Thread count.

Thread count is an indication of the quality of fabric – the higher the count, the better the quality for any one fabric – and can be used in judging ravelling, shrinkage and durability. The higher count also means less potential shrinkage and less ravelling of "seam" edges.

Quality is always reflected in price.

Thread count is sometimes printed on the selvage of percale and on labels of bed sheets. Mail order houses frequently give thread count since customers must judge the quality from printed information rather than from the fabric itself.

Advertising thread count.

A standard method of making a thread count may be found in the American Standards for Testing Materials (ASTM). The count is made with a thread counting instrument.

Thread count test machine.

It is possible to use a “hand” method by which the area is measured by a ruler and count by sight or yarns ravelled off and counted.

Percale fabrics have, in the past, had a standard thread count of 80 x 80 and were called 80-square fabrics. In general, a bed sheet with a higher thread count will be more durable and feel softer. A thread count of 200 is a good standard; a count of 300 will be noticeably softer.

A solid blush 300 thread count full (double bed) size sheet set - 100% Egyptian.

Balance is the ratio of warp yarns to filling yarns in a fabric. A well-balanced fabric has approximately one warp yarn to every filling yarn or a ratio of 1:1. Examples of typical unbalanced fabrics are cotton broadcloth with a thread count of 144 x 76 and a ratio of about 2:1 and nylon satin with a thread count of 210 x 80 and a ratio of about 3:1.

Cotton broadcloth (natural).

Balance is helpful in recognizing and naming fabrics and in distinguishing the warp direction of a fabric. Balance is not always related to quality. Balance plus thread count is helpful in predicting slippage. If the count is low, there seems to be more slippage in unbalanced fabrics than there is in balanced fabrics.


Reference:
[1] N. Hollen and J. Saddler, Textiles, 3rd Edition, MacMillan Company, London (1968).

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