As the size of lighting gel required depends entirely on the type of light with which it will be used, gels usually come
in rolls or sheets that are then cut to
the correct size. This is especially true
in photography, where often only a very small amount of gel is required for use
with a hotshoe flashgun. For this reason, many manufacturers offer small kits
for photographers with a number of different-coloured gel swatches. Despite being manufactured from materials designed to withstand very high temperatures, lighting gels do wear out over time. The colour can begin to fade and the material can become quite brittle and just flake away.