Roll film is any type of spool-wound photographic film. The film is protected from white light exposure by a paper backing as opposed to film which is protected by being wound forward in a cartridge. It was originally referred to as “cartridge” film due to its resemblance to a shotgun cartridge. The film can be loaded in daylight since it has an opaque backing paper. During use, the spool of roll film is pulled across to an identical spool as exposures are made, once the original spool is used up it is transferred over and the new spool feeds into the newly emptied one.
Peter Houston invented the first roll film camera in 1881. His brother David Houston invented the first holders for flexible roll film. He licensed his patent to George Eastman in 1881. However, in 1889 he sold the patent outright to Eastman. He did continue to develop patents for the camera and camera parts and in 1912 when he died his estate passed those patents to Eastman.