fixer
Nota de aplicación
In silver gelatin photographic processing, a fixing bath contains a chemical, either sodium thiosulfate or ammonium thiosulfate, used to remove light sensitive silver halides from a photographic image and thus stabilize prints or film, fixing it, after it has been exposed to light. Ammonium thiosulfate was later adopted as a fixing salt because it acts three to four times faster, though is less stable.