Since its invention in 1958, spandex, also known as elastane or by its trademark name, Lycra, has revolutionized the textile industry and clothing design. Unlike its predecessors, rubber and elastic fibers, spandex can stretch up to 500 times its starting length and then return to its original size. It can also be spun into fine filament threads, making it ideal for blending with other fibers to add elasticity.
Knit fabrics can be manufactured with or without spandex. A typical example of a non-spandex knit is a sweatshirt knit. While comfortable, these knits lack “memory,” meaning over time, they bag out in places where the body bends: think knees, elbows, and the seat. Even washing and drying in high heat won’t coerce the fibers back into shape once they have stretched…