Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. fixative

Additional parents:

1. top of the aat hierarchies
2. Materials Facet
3. Materials
4. materials
5. materials by function
6. photographic materials

Anotations

Scope note:

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.