Most Cycling, Running, and Fitness clothing is made of, or partially made of Polyester for its wicking properties that are hard to match by any other fabric, natural or man-made. Acrylic is often used in insulation layers because it is inexpensive and has good insulation properties. Neoprene is non breathable, water resistant thermal material. It offers excellent protection from cold and used in fabric for shoecovers and gloves. Nylon spandex, the base for most cycling-short fabrics has great stretch and durability. However, nylon spandex does not have the ability to wick moisture, a major benefit when you're sweating, and breathe until a finish is applied, or until the fabric is knitted a special way. For example, spandex is now mixed with other yarns such as polyester to promote moisture transfer and breathability.