Photographic fixer

For other uses, see Fixer (disambiguation).
A black and white photographic print in a tray while being processed after exposure to light under a photographic enlarger. Typically three trays are used containing either developer, stop bath, or fixer, in that order. The print must then be rinsed in water to removed the fixer.

Photographic fixer is a mixture of chemicals used in the final step in the photographic processing of film or paper. The fixer stabilises the image, removing the unexposed silver halide remaining on the photographic film or photographic paper, leaving behind the reduced metallic silver that forms the image. By fixation, the film or paper is insensitive to further action by light. Without fixing, the remaining silver halide would darken and cause fogging of the image.