Very thin polymer plastic can be added to glass, either during the manufacturing of a unit or as an aftermarket add-on, to change the properties provided by the glass. The film, generally referred to as window film, as it is most frequently applied to windows, can be either functional or decorative in nature.
After-market window film can be used as part of safety or security glazing anchoring systems, providing an extra layer of protection to catch broken glass and slow the entrance of debris into a space that has been breached.
Film also provides options for less expensive and less permanent decorative options for glass, ranging from different colors to a frosted or etched look, nearly all of which can be cut and layered to create images, patterns or depth. The most commonly known window film application, though, is for solar control, such as the tint on car windows. However, solar control window film is available in different degrees of tint, spanning from nearly transparent to the darkest tint, what most people know as “limo tint.”
After a rigorous cleaning of the glass, window film is applied with a solution of soapy water, which creates the surface tension needed to hold the film in place. Most window films have an adhesive that bonds with the glass once the water solution dries, though there are some that are adhesive free.