Fleece is a soft fabric used as a substitute for wool in clothing or other garments. American company Malden Mills originated Polartec, a type of synthetic fleece fabric. After Polartec's introduction, fleece material, regardless of the manufacturer, began to be called "polar fleece."
Polar fleece is a polyester fabric with a two-sided pile. It is an extremely durable fabric that resists moisture, dries quickly and keeps the wearer warm. Due to its construction, fleece does not pill, even when it is worn frequently. It is lighter and warmer than wool, making it ideal for active wear. Polyester fleece is a highly versatile fabric and has been used as a lining in deep-sea diving suits, as underwear for astronauts and as ear-warmers for winter-born livestock.