A white crystalline compound, used in solution for coating paper prior to marbling, for setting dyes on fabrics and other applications. Also sometimes referred to as Potassium Aluminum Sulfate. Al2
O This product looses 18 H2
O at 92.5o
C and becomes anhydrous at 200o
C. It forms cubic or octahedral crystals that are soluble in cold water, very soluble in hot water, and insoluble in ethanol and acetone.
Alum is often used in marbling to help the pigments adhere to the paper. Check out our "how-to" on alumming paper for marbling