All 4x5 cameras can "take" a polaroid-style instant film back. They insert into the camera just like a conventional film holder. Alas, Polaroid has discontinued all film production. Fuji DOES make 4x5 instant film in 10 sheet pack-film format. These products can be used in certain Polaroid film backs, as well as Fuji makes an instant-film back. Some older wooden cameras may not have enough "room" under the ground glass to insert a pack-back. While, probably the bulk of 4x5 instant film is used for testing exposure and composition, Polaroid DID make a b/w instant film that had a useable negative (Type 55), which many people loved for its near grainless image with beautiful tonality. You will find polaroid backs for individual 4x5 sheets as well as pack-film. Fuji only makes pack film. Polaroid made both individual sheets and at one time pack-film.