Alum is the most common mordant. If you are not sure what you want to do, mordant with alum, and use the others as additives. Alum does not affect color. It is usually used with cream of tartar, which helps evenness and brightens slightly. Three ounces of alum and one of cream of tartar is a good start; if you have heavy wool, use four ounces of alum. Too much alum makes wool sticky. Alum mordanted wool stores well, wet or dry.
- Alternative Names: Potassium Aluminum Sulphate
- CAS Number: 17927-65-0
- Function: Mordant for Protein Fibers
- Typical Use Rate: 3 - 4 oz. per pound of fiber
- Package Size: 1.0 lb.