Anti-graffiti window film is a clear film applied to the surface of the glass that is exposed to vandalism. It also goes on other smooth, non-porous surfaces such as mirrors, stainless steel and elevator panels. It is sacrificial: when someone scratches, etches or tags the glass, the film takes the damage instead of the glass underneath.
When the film is damaged, we remove it and install new film. The film uses a removable adhesive designed to come off with the film, so the surface can be prepared for the replacement film. Replacing film is usually far simpler than replacing scratched or etched glass. There is no fixed replacement schedule. The film is replaced when it is damaged, so the sacrificial layer can keep protecting the surface underneath. Every time the film gets damaged, it has done its job.
For a real example, see our Nordstrom Rack anti-graffiti film case study, where we replaced etched and scratched film with 6 mil Graffitigard. For how old film of any kind is removed and replaced, see How Do You Replace Old or Failing Window Film?
