Lycra. Coloured scanning electron micrograph (SEM) of lycra fibers. Lycra is the brand name of the polyurethane or spandex fibre made by Du-pont. It is basically a grafted polymeric fibre and the speciality of the fibre is the very high extensibility (up-to 400%). The elasticity and strength of spandex has been incorporated into a wide range of garments, especially in skin-tight garments. A benefit of spandex is its significant strength and elasticity and its ability to return to the original shape after stretching and faster drying than ordinary fabrics. For clothing, spandex is usually mixed with cotton or polyester, and accounts for a small percentage of the final fabric, which therefore retains most of the look and feel of the other fibers. Magnification: x25, when printed 10cm wide.