Lighting Gels

Filters were originally made from gelatin [hence “gels”] but by the 1950’s Strand had developed acetate filters. Nowadays there are two raw materials used in making colour filters, polycarbonate and polyester. Polycarbonate is the material able to endure the highest heat and is liable to give the longest possible life. There are two fundamental ways of manufacturing filter. The cheapest way is for the manufacturer to buy clear polyester film and to dye it on one or both surfaces. You can tell a film that is made this way because the colour can be removed by wiping the surface with a solvent or by scratching it. In most cases it will be a perfectly serviceable filter, but a problem will arise if you use it in colour scrollers. This is because during the manufacturing process the film is extruded thick and then stretched and rolled to produce the final thickness. This process puts a linear orientation into the film that causes it to shrink in width when heated. It will be prone to failure in colour scrollers. The best filters are produced from pellets of the raw material that are deep dyed then extruded to the correct thickness and finally coated with a clear film on each side. Supergel is the only filter made this way. Lee Filter numbers were developed by Fred Bentham of Strand. The numbering system was widely adopted in Europe. Rosco E-Colours were developed using surface coated polyester to match these European numbers. Please note that Rosco are no longer providing their swatchbooks Free Of Charge, so please be aware we will not be able to waive the fee.