A clear, flexible film made from cellulose. It first appeared commercially in the United States in 1924, and it revolutionized the packaging industry, which had been using opaque waxed paper or glassine as wrapping materials. Cellophane was also the first transparent mending tape. By 1960, petrochemical-based polymers (polyolefins) such as polyethylene had surpassed cellophane for use as a packaging film. Nevertheless, 50,000 tons (45,000 metric tons) of cellophane are used in the United States each year for packaging because cellophane gives a material that is stiffer and more easily imprinted than are polyolefin films.