Fabric Glossary: Terms Starting with S

S Number or Super Number

Originating in England, the S number is a grading system for high-quality wool used in suits, indicating the maximum fiber diameter allowed for a particular grade. For example, Super 80 wool has fibers of 19.75 microns or finer, while Super 250 wool has fibers that are 11.25 microns or finer. Higher S numbers indicate finer, rarer fibers and command higher prices. Ultra-high S number wools are used in luxury suits costing upwards of $10,000. While these suits offer exceptional softness and appearance, the fine fibers are delicate and less durable over time.

S Twist

Also known as left-hand twist, reverse twist, filling twist, or crossband, S twist is one of the two directions in which yarn can be twisted. The other is Z twist (right-hand twist). To avoid confusion with the terms "left" and "right," the letters S and Z are used to denote the twist direction, based on the slant of the yarn resembling the middle stroke of the letters S or Z.

Sailcloth

Sailcloth refers to heavy, durable canvas fabrics used for making sails. Traditionally made from cotton, linen, or jute, modern sailcloth is predominantly woven from polyester or nylon fibers and treated for moisture resistance, saltwater durability, and UV protection.

Sales Rep

A sales representative in the fabric industry is an agent who showcases and sells fabrics on behalf of fabric companies to retailers, designers, or manufacturers.

Sateen

Sateen is a fabric made from combed, mercerized cotton or cotton blends, woven in a satin weave. It has a soft, glossy surface and is available in various weights, commonly used for shirting and bed linens.

Satin Organza

Satin organza is a sheer, crisp fabric with a satin weave, often used in formalwear and overlays.

Satin Weave

A satin weave is one of the three fundamental fabric weaves (along with plain and twill). It is characterized by long floats of warp or weft yarns that create a smooth, lustrous surface with minimal interlacing. Charmeuse is a type of satin weave fabric with a slight nap, which requires careful pattern layout to ensure all pieces are cut in the same direction for consistent appearance.

Scalloped Edge

A scalloped edge is a decorative fabric or lace finish featuring a series of repeated convex curves, resembling the edge of a scallop shell.

Schiffli Embroidery

Schiffli embroidery is produced by a multi-needle industrial embroidery machine invented in the 19th century. It replaced hand embroidery by enabling mass production of intricate designs and certain types of lace. The term "Schiffli" means "little boat," referring to the boat-shaped shuttle used in the machine. Schiffli lace, also called chemical lace, is created by embroidering on a fabric that is later chemically dissolved, leaving only the embroidered lace.

Scotchgard

Scotchgard is a trademarked fluorocarbon-based chemical spray that provides fabrics and carpets with water, grease, and stain resistance. Eco-friendly alternatives are now available.

Secondary Colors

Secondary colors are formed by mixing two primary colors and include orange, green, and purple. Both primary and secondary colors are considered pure hues on the color wheel.

Seersucker

Seersucker is a fabric with a puckered, crinkled surface alternating with smooth sections, often arranged in stripes. It is woven using two sets of warp threads: one group woven tightly and the other loosely, creating the characteristic texture. Seersucker is primarily made from cotton or cotton blends but can also be woven from silk. It is available in various weights.

Selvage

The selvage (or selvedge in British English) is the finished edge of a fabric running parallel to the warp threads. It prevents fraying by looping the weft threads back over the warp. Selvages tend to shrink faster than the rest of the fabric, so it is advisable to remove them before sewing.

Sequin

Sequins are small, shiny discs or shapes made of plastic or metal, sewn onto fabrics for decoration. They can be flat or cupped and are also called paillettes, diamante, or spangles. Paillettes were traditionally made from real gold or silver but are now usually brass or iron, with brass being rust resistant. Sequins typically have one or two holes for attachment, while spangles have a single hole at the top and hang freely. Sequin transfers are heat-applied sequins without holes, also called spangle or threadless sequin transfers. Hotfix sequin transfers use heat-activated adhesive but still have holes. Equipment that applies rhinestones, hotfix, sequins, and spangles is often called "bling machines," which work faster than embroidery machines. Avoid ironing or steaming sequins or metal paillettes, as heat can dull, melt, or mark them.

Serge

Serge is a twill weave fabric similar to denim, khaki, or gabardine. It can be made from wool, cotton, synthetics, or blends and is available in various weights and textures.

Serger, Serging

A serger is an overlock sewing machine designed to finish fabric edges by trimming and overcasting to prevent fraying. Serging is the process of using a serger to finish raw fabric edges.

Sericin

Sericin is the gummy protein coating silk fibers, removed during silk processing.

Shade

In color theory, a shade is a pure color mixed with black, resulting in a darker version of the original hue without any white or gray.

Shantung

Shantung is a silk fabric with a slubbed texture, characterized by irregularities in the weave.

Sharkskin

Sharkskin is a suiting fabric woven with two-color threads, usually one white or off-white, creating a subtle two-tone effect. The weave can be plain, twill, or basket, with patterns including stripes, plaids, windowpanes, nailheads, and birdseyes. Fibers used include silk, mohair, worsted wool, blends, and synthetics.

Sheen

Sheen refers to the brightness or luster of a fabric’s surface. Silk naturally has a distinctive sheen due to its fiber structure.

Sheer

Sheer fabrics are very thin woven or knitted textiles that can be flimsy or crisp, and range from transparent to semi-transparent.

Sherpa Fleece

Sherpa fleece is a knit fabric with a thick, fluffy texture resembling sheep’s wool. It is lightweight and insulating, commonly used as lining for apparel and blankets. It can be made from cotton, polyester, or blends.

Shot Fabric

Shot fabric is an iridescent textile created by weaving differently colored warp and weft threads, producing a shimmering effect.

Shibori

Shibori is a dyeing technique involving folding, twisting, or bunching fabric and binding it before dyeing to create distinctive patterns.

Shiny

Shiny fabrics have a smooth, glossy surface resembling a mirror or metallic finish. They are often made with satin weaves. Silk charmeuse and satin naturally have a shiny surface due to their weave structure.

Shirting Textures

Common shirting fabrics include broadcloth, chambray, denim, dobby, end-on-end broadcloth, flannel, herringbone, jacquard, linen, madras, melange, oxford cloth, pinpoint oxford, poplin, royal oxford, sateen, seersucker, and twill.

Shrinkage

Shrinkage is the reduction in fabric length and width after laundering, whether by washing or dry cleaning.

Silk

Silk is a natural protein fiber produced by silkworm larvae and obtained by carefully unwinding the cocoon they spin. The silk fibers are then cleaned, spun into yarn, and woven or knitted into fabric.

Silk and Wool

Silk and wool blended fabrics combine fibers from both materials and can be woven in various weights and weave types.

Silk-like

Silk-like fabrics are synthetic textiles engineered to resemble silk in appearance and texture.

Silky

Silky refers to fabrics made from synthetic fibers designed to imitate the look and feel of silk.

Silver

In yarn production, silver is a loose, soft, untwisted strand of fibers produced during the carding process.

Sizing

Sizing is a treatment applied temporarily or permanently to fibers, yarns, or fabrics to add body, strength, smoothness, or weight. It is applied to warp threads to improve weaving performance or to finished fabrics to enhance hand and appearance. Common sizing agents include starch, gelatin, and resin.

Slub

A slub is a thick or uneven spot in yarn or thread, often visible on fabric surfaces. Natural fibers like cotton, wool, linen, and silk commonly exhibit slubs. Some silk fabrics, such as silk shantung and silk doupioni, intentionally incorporate slubs for texture.

Soy Fabric

Soy fabric is a man-made cellulosic fiber produced from leftover soybean hulls from tofu manufacturing. The soy proteins undergo chemical processing involving heat, alkalis, or enzymes, followed by filtration and extrusion through spinnerets to form fibers. Formaldehyde is sometimes used to cross-link fibers, enhancing length and strength. Soy fabric can be woven or knitted into textiles.