Microfiber is synthetic fiber finer than one or 1.3 denier or decitex/thread. This is 1/100th the diameter of a human hair and 1/20th the diameter of a strand of silk. The most common types of microfibers are made from polyesters, polyamides (e.g., nylon, Kevlar, Nomex, trogamide), or a conjugation of polyester, polyamide, and polypropylene (Prolen). The shape, size, and combinations of synthetic fibers are selected for specific characteristics, including softness, firmness and resilience.