Commonly known as alum. It is used as a mordant in fabric dying and as a pre-wash for organic fabric cloth to enable maximum penetration of the fabric dyes. Used on its own or combined 1:1 with soda ash by volume dissolve mix in warm water and pre-wash fabric by hand or machine wash.
Also used as a preservative in dextrine or corn starch glue preparation in hot cooking process. Add a teaspoon of alum to 1L water over a slow fire and stir in 500g starch powder until mixture thickens into a glue. Similar use in paper mache as a preservative in the paper mash to avoid mash deterioration noted by a foul odour.
Alum is also a tanning chemical use in taxidermy as a tanning salt.