In any color filter, the colorants or dyes eventually migrate away from the hottest area, which causes fading and discoloration. The rate at which the filter fades is a function of the dye employed and the depth of penetration by the dye into the base material. When simply coated on the surface, a dye will sublimate from the base into the air more easily than a dye that is uniformly locked by chemistry throughout the material. The greatest color-stability is achieved when the dye is dispersed uniformly through an extruded plastic base, as it is in Rosco Supergel filters.
Supergel is the most heat-resistant filter available. Unlike other plastic filters, which begin with pre-formed rolls of clear polyester, Supergel’s distinctive body-colored manufacturing process yields a polycarbonate filter that is extruded into the exact thickness required for each color. The polyester used in other filters, however, is essentially stretched into shape, which leaves tension memory that can cause the film to pucker and distort when placed on hot lights. In contrast, Supergel is extruded into its final state, allowing the film to maintain its shape in high temperatures. This is particularly advantageous when using color-scrollers, where puckering could cause the scroll to bind.
Inherently Flame Retardant
Rosco Supergel filters are inherently self-extinguishing. An advantage of manufacturing Rosco’s Supergel filters from raw, polycarbonate resin is our ability to modify the chemistry of the plastic. Recognizing the global importance of fire prevention, Rosco includes a fire retardant additive in our resin formulation to create the only inherently flame retardant color filter in the world. Supergel has been tested according to the strictest standards in the US and Europe, and is the only filter range to have earned the demanding German B1 flame-rating. It has also obtained the French M1 and the Italian CI flame-ratings, as well as NFPA classifications.