Potassium Alum 100 g

Potassium alum, potash alum, or potassium aluminium sulfate is a chemical compound. A mixed salt of aluminum and potassium from sulfuric acid and at room temperature it is in the form of a white powder, similar to the fine salt from kitchen, colorless and odorless. Since ancient times it has been used in numerous productive activities and in various sectors. Alum has been used since antiquity as mordant to form a permanent bond between dye and natural textile fibers like wool. Aluminum hydroxide from potassium alum serves as a base for the majority of lake pigments. In traditional Japanese art, alum and animal glue were dissolved in water, forming a liquid known as dousa (ja:礬水), and used as an undercoat for paper sizing. In violin making it is used as a fixative for alizarin (madder lacquer) and as an additive to make animal glue waterproof.