Film Bases


Physical components of film and the differences between each film base

Emulsion: a photosensitive gelatin binder that carries the image; the thinner part of the film.

Base: flexible support on which photographic emulsions are coated; the thicker part of the film

Source: The Film Preservation Guide. NFPF. Page 8

The Three Bases


  • Extant from 1893 to the early 1950s
  • Highly flammable
  • Only produced as 35mm
  • Often labeled NITRATE FILM on the film base’s edge


  • Extant from 1909 to present
  • Nonflammable substitute for nitrate
  • Also known as Safety Film
  • Often has SAFETY FILM printed along the film base’s edge


  • Extant from mid 1950s to present
  • Thinner and stronger than acetate
  • Most chemically stable film based used today
  • The most transparent of the three bases
Source: The Film Preservation Guide. NFPF. Page 8