Protection from UV light can be accomplished by a colorless film that addresses only the UV spectrum. The adhesive system used in window films rejects (absorbs)some UV radiation up to 380 nm, and depending on the manufacturer, UV inhibitors are added to the polyester. As UV is one of the main sources of fading, it can prolong the life of fixtures and fittings.
Heat control window films can provide huge air conditioning savings, in existing automotive with energy inefficient windows. Modern windows with low-solar-gain glass do not need retrofit films, but since most of the existing windows do not have a low SHGC, window films make a lot of sense as a retrofit energy improvement.
Heat rejection films are normally applied to the interior of flat glass windows to reduce the amount of infra-red, visible light, and ultraviolet (UV) radiation entering windows. Such films are usually dyed or metallized (which can be transparent to visible light) to convert incoming solar radiation to infra-red radiation.