any of a class of synthetic plastics, resins, and oils used to manufacture many products. By varying the starting reagents and the process of forming, a material may be produced that is hard and transparent, soft and resilient, or a viscous liquid. Acrylic compounds are used to make molded structural and optical parts, jewelry, adhesives, coating compounds, and textile fibres. Orlon and Acrilan are trademark names of acrylic fibres; Lucite (q.v.) and Plexiglas are glasslike acrylic materials. See also vinyl compounds.