Like photographic prints and glass negatives/transparencies, film-based media are composite objects, consisting of a film support and a binder/emulsion with an image-forming or recording substance suspended in it. Film has been used as a support for many different types of media since the late 19th century, including various types of still photography film (such as 35 mm roll film, portrait and commercial sheet film, x-ray film), slide film, microfilm, amateur movie film (8mm and 16mm), and motion picture film.
Three types of film have been used as supports: nitrate, acetate, and polyester films (with the latter being the most stable). Many modern film-based media use a polyester film base, but not all. The characteristic deterioration of these films will be discussed in this section, along with typical deterioration mechanisms of the binder and image-forming materials.
Film is also used as a base for magnetic tape (audio, video, and computer tape), but these media are discussed separately in this session because of their unique characteristics; see Inherent Vice: Magnetic Media.