Acrylic is a manufactured fiber formed from any long-chain synthetic polymer composed of at least 85% acrylonitrile units by weight. The goal in developing acrylic was to have a fiber to compete with wool in staple form and silk in filament form. Currently, only staple acrylic fibers are produced. The specific gravity is low (1.17), resulting in a soft, but not bulky hand. Acrylics also have excellent resistance to sunlight; long exposures do not affect their strength or color. The most common uses for acrylics today are socks, knit sweaters, tenting, awnings, and loungewear.