fixingsalt
nounUK /ˈfɪksɪŋ sɔːlt/
US /ˈfɪksɪŋ sɔlt/
A special salt used to keep colors bright when dyeing cloth.
The dyer added fixingsalt to the bath so the red would not wash out.
OTHER MEANINGS
2. A salt mixture used to set or stabilize a photographic image.
Old photographers used a fixingsalt bath to make prints permanent.
3. A preservative salt blend used in curing or treating materials.
The tanner applied fixingsalt to keep the hide from spoiling.
4. Any salt compound that locks a substance in place during a chemical process.
The lab technician chose a fixingsalt to bind the pigment to the sample.