photographic process in which gelatin is used as the dispersing vehicle for the light-sensitive silver salts. The process, introduced in about 1880, superseded the wet collodion process, in which a wet negative was produced from a nitrocellulose (collodion) solution applied to a glass plate immediately prior to exposure. This chemical treatment necessitated the presence of a darkroom wherever a photograph was to be made. The development of a process in which a sensitized gelatin emulsion could be dried on the plate and stored, protected from light, for months before use revolutionized the world of photography. Gelatin is still the standard binding medium for the silver halide crystals used in ordinary photographic film.