Supergel is the original – and still the most durable – of the high temperature filters. The range is created through a unique manufacturing process which results in a body coloured product, that is, a filter whose colour can’t be separated from the base. The process starts with powdered resin and dye being fed into an extruder. Under intense pressure and heat approaching 600ºF, the drive screw combines the melted resin and dye into a coloured "honey". This coloured mixture is pushed through a die which forms it into a coloured plastic film 61cm wide. The excellent performance of this engineered filter on a hot theatre light is a result of both the higher temperature resistance of the polycarbonate base polymer combined with the unique manufacturing process that converts the “honey” mixture into a theatrical colour filter.

Lee and other manufacturers supply a “high temperature” filter, also fabricated on polycarbonate. But they use the surface coating method of manufacturing, the same process used in Rosco’s E-Colour+ and the rest of the Lee Filter range.

Both Rosco’s E-Colour+ and the basic range of Lee Filters^®; are patterned on the Cinemoid filters, introduced in Europe in the early 1950's. For that reason, both Lee and Rosco E-Colour+ offer the same filter names, numbers and roll sizes. Users can safely order by name, number or colour in either brand and be assured of exact matches.

These Lee/Rosco colour filters are all manufactured in the same process, on the same plastic base. The colour, a solvent-based lacquer, is painted on one or both sides of a polyester base. This is called “surface coating”, one of the oldest and simplest methods of creating filters. The resulting filter product, however, is somewhat more susceptible to fading from continuous use in theatrical spotlights.

Although only recently introduced in to Europe, Roscolux is the most widely specified theatrical colour filter range in the world. Theatrical lighting people throughout North and South America have, over the past 50 years, made this range a staple in theatres everywhere. Part of the reason for this popularity is that many Roscolux colours have no matches in other brands.

Roscolux is manufactured using a deep-dyeing process in which clear polyester film is passed through a bath of heated solvent suffused with dye, penetrating into the base film. With the dye inside the plastic, more extreme temperatures are required to cause the dye particles to sublimate out of the film. Deep-dyed filters are, therefore, more resistant to fading and designed for continuous use on theatrical lights.