Fabric is the medium in which your design idea comes to life. The more robust the knowledge of fabrics, the more success there will be in the execution of design ideas. In this article, I will give an overview of fiber, yarn, fabric construction, fabric qualities, and fabric finishes.
Fabric starts first as a fiber, then is spun into yarn, then constructed into a woven or knit fabric (structure), then finished for appearance or performance qualities.
Fiber: A fiber is the smallest unit of fabrics. Natural fibers like cotton, wool, and flax are staple fibers, meaning the fibers are short in length. Man-made fibers like rayon, nylon, and polyester are filament, or long and continuous, fibers. The exception to this rule is silk, a natural fiber, which is considered a filament because of the long and continuous protein fiber harvested from the silk worm.
Yarn: A yarn is made from fibers. There are two main types of yarns separated by fiber length: 1) Staple spun yarns are made from short staple fibers, or long filaments that have been cut into staples and require some twist 2) Filament Yarns are made from long, continuous fibers and require no to little twist.
Yarn twist: Yarns are twisted to hold fibers together and increase uniformity and strength. Twist is measured by the number of twist per unit length and can be defined as none, very low, low, average, and high twist. Yarn is also categorized by direction of twist, as yarns can twist clockwise (s-twist), or counter-clockwise (z-twist.) Yarn twist impacts the yarn’s appearance, strength, and absorption.Yarns composing fabrics with high absorbency, like towels, can have low twist, while yarns composing fabrics with crepe texture have high twist.
Yarns can be classified into simple, novelty, and textured yarns.
Simple yarns: characterized by uniform size and surface. Can be any of the below:
•Single yarns are the most simple and are produced by twisting together staple or filament fibers.
•Ply yarns are made by twisting two or more single yarns together.
a 2-ply yarn is equivalent to two single yarns twisted together
a 3-ply yarn is equivalent to three single yarns twisted together, etc.
•Cord yarns are made by twisting two or more ply yarns together.
•Rope yarns are made by twisting two or more cord yarns together.
Novelty yarns: yarns engineered for decorative surface affects. They may be single or ply and contain several colors or fiber types for visual variation. Examples of novelty yarns include slub, flock, boucle, or chenille yarns.
Textured yarns: yarns composed of thermoplastic filaments like nylon and polyester can be heat-set or yarns composed of natural fibers can be chemically treated to form textural affects. Textural affects provide variations in fabric properties like greater stretch, bulk, or opacity.
Yarns are either woven or knitted together.
Woven: two sets of yarns interlocking together at right angles to create a multitude of patterns including plain, twill, satin, basket weave or decorative patterns like jacquard waves.
Knit: a continuous yarn arranged in flexible interlocking loops. Knit fabrics are inherently stretchy. Knit and purl stitches are the foundation of all knitted fabrics or garments. A knit stitch is a loop drawn through the front of the last stitch. A purl stitch is drawn through the back. Plain knits have knit stitches at the front and purl stitches at the back of the garment. Purl knits can be fairly chunky and often show only back loops on both the face and reverse of the fabric. Rib knits alternate sets of knit and purl stitches in the same row, forming ridges or ribs. Rib knits are categorized by the number of knit and purl stitches in the pattern, like 1x1 rib, 2x2 rib, etc. Novelty patterns, like cable stitches, can be creating by adding, dropping, alternating, and crossing knit and purl stitches.
Once a fabric is knit or woven, it can be texture finished (ex. napped, brushed, embossed), temporarily finished (ex. softened, weighted, sized), or finished for performance attributes (anti-bacterial, flame resistant, pre-shrunk).
The fiber content, yarn type, fabric structure, and finishing process will determine the final fabric quality. Many fabric qualities can be reproduced in different fibers. For example, For example, “jersey knit” fabric can be composed of cotton, wool or silk. In addition, many fabric qualities can be imitated using man-made fibers or a combination of man-made and natural fibers.
The combination of the fiber content, yarn type, structure, and finishing of a fabric will determine the resulting fabric quality. Fabric quality are qualified by tactile properties like hand, drape, and weight.
Hand: the “feel” of fabric against the skin. There are many different words to describe the handfeel of a fabric including: soft, dry, stiff, sticky, silky, smooth, warm, cool
Drape: The way fabric folds and hangs off of the body. Stiff fabric like cotton canvas have less drape, while fluid fabrics like silk georgette have more drape.
Weight: The weight of fabric is listed as either grams per square meter (GSM) or ounces per square yard (OZ/ SQ2.) A lightweight fabric is typically between 30-150 GSM, medium weight 150-350 GSM, and heavyweight is typically over 350 GSM
these are the types of questions I ask when sourcing fabric:
What is the fabric most suitable for?
What is the fiber content and how will that affect the fabrics performance?
How does a fabric feel/ what is the hand?
What is the construction?
How is the drape?
How will the fabric handle while sewing?
Will the fabric shrink, stretch or fray?
Can the fabric be home laundered?