I mentioned elastane in the Introduction to Fibers page, but there’s always room for more information.
Spandex is a brand name that has become synonymous with the generic thing that it represents – like Kleenex and Xerox and Google. Technically, Spandex is a trademarked fabric using elastane as one of its main components.
What’s elastane? Pure awesome, that’s what. Elastane is very… elastic – big surprise. The great thing about elastane is, unlike the stretch yarns that preceded it, elastane can be stretched and recover its original shape almost indefinitely. Previously, elasticated fabrics and knits would, sooner or later, give up and get saggy and permanently stretched out. Just imagine Spiderman with baggy knees. Ridiculous. Furthermore, it’s much more durable than the fabrics that preceded it, meaning longer-lasting garments.
Elastane is present in a lot of fabrics: Spandex, Lycra, many jerseys and plain knits. It’s used in sportswear, lingerie, hosiery, medical textiles and much more. It’s quite useful and therefore omnipresent. Some blends might use as little as 2% elastane in order to give it just that tiny bit of essential stretch. Your typical store-bought bodysuit has about 30% spandex or elastane in it.
Spandex is a knit fabric with a high degree of four-way stretch. It can be shiny on both sides, or shiny only on the right side and matte on the other. It’s available in a range of weights – from light to heavyweight. Heavier spandex has a reduced degree of stretch and can be really hot to wear, as there’s barely a natural fiber to found in it. The original Star Trek: The Next Generation uniforms were made from a heavy-weight spandex, turned wrong-side out. I can only assume the actors had great foundations under those things because… wow.
Spandex comes in every color of the rainbow and practically every print you can imagine. If you’re shopping for spandex online, always get a swatch before committing to it, as there’s no industry standard for the fabric weights and you don’t want to end up with several yards of something too sheer for your costume.
You also want to be sure that it’s going to stretch enough for the intended purpose. If you’re sewing from a pattern that requires a four-way stretch, the edge of the envelope will, with luck, include a “stretch gauge” that you can test your swatch against. As I said, heavy spandex won’t stretch as much as a lightweight spandex and that’ll be an issue if you intend to do acrobatics or dance in your costume.
Pre-wash spandex in cool water with a mild detergent and let it hang to dry. Avoid throwing it into the dryer as much as possible, as that will shorten the usable life of the elastane. Use a cool iron without steam when pressing.
Stitching it is a challenge, because it IS a knit. Your needle choice depends on the type of spandex you’re sewing. Most seamsters will default to a ball-point needle for jersey fabric, but if you have a chance, ask the retailer what’s the best choice. Whatever needle you use, be ready to change it often, as this fabric is hard on machine needles. If your machine is skipping stitches, immediately put a fresh needle in and see if that helps.
When ironing, use a low-temperature setting. Elastane does NOT like hot irons and can scorch easily.
Stitch type is another pitfall waiting to happen. Odds are if you’re using spandex, you need seams that can cope with the costume’s moving on your body. In most cases, a short and narrow zig-zag stitch will do the trick. Again, if you have an opportunity to speak to an expert when buying the fabric, do so.