Four-way stretch spandex

A smooth, clingy knit fabric that stretches in all directions, ideal for bodysuits, superhero suits, and tight-fitting costume bases.

Four-way stretch spandex (sometimes sold as Lycra, which is a brand name) is a knit fabric made with elastane fibres so it can stretch both along its length and across its width, then spring back to its original shape. That recovery is what makes it popular for close-fitting costumes like superhero suits, dance leotards, catsuits, and any base layer that needs to follow the body's movement without bagging or pulling. Because the fabric hugs the form so well, patterns for it are often drafted a little smaller than your body measurements so the stretch does the work of fit. The fabric comes in a wide range of weights, finishes, and textures. Matte spandex has a flat, even surface good for painted designs or sublimation printing. Foiled and holographic versions give a shiny, reflective finish. Velvet spandex adds a soft pile. Heavier weights hold their shape better for structured panels, while lighter weights are easier to sew in smooth curves. Colour and print options are very broad, and custom sublimation printing services can print a full illustrated design onto polyester-based spandex before you cut and sew. Sewing spandex successfully usually means using a stretch or ballpoint needle, a narrow zigzag or stretch stitch rather than a straight stitch, and polyester thread that can flex with the fabric. An overlocker (serger) gives the neatest, most durable seams and trims the seam allowance in one pass. Regular straight stitches will pop under tension. On a standard machine, let the feed dogs move the fabric rather than pulling or stretching it as you sew. Pins can leave marks, so fabric clips are often easier. Because spandex is slippery and shifts easily, cutting accurately matters. Many makers cut a single layer at a time with sharp fabric shears or a rotary cutter on a self-healing mat, weighing the pattern pieces down rather than pinning through the fabric. Note the grain line and the direction of greatest stretch before cutting, because placing panels the wrong way round will affect how the finished costume fits and moves. Printed designs go on before cutting; if you plan to add painted detail, many makers do it after sewing, with the suit on a dress form, so the design lines up with the body.