Acrylic, a synthetic fiber, was developed in 1941 by the DuPont Corporation, and introduced to the public in the early 50s. DuPont trademarked acrylic using the name Orlon. Acrylic is used as a soft and warm wool-like staple fiber, most often for sweaters, blankets, and other uses one would expect for wool. It can also be made to imitate cotton. Acrilan (Monsanto) and Creslan (American Cyanamid) are two other U.S. brand names for acrylic that can be found in vintage garments, but are no longer produced.
The U.S. Federal Trade Commission defines acrylic as “a manufactured fiber in which the fiber forming substance is any long-chain synthetic polymer composed of at least 85% of weight of acrylonitrile units.”