Casein Earth Paint
History: Derived from milk, Casein Paint dates back to Asian cave paintings, and it was widely used up until the Renaissance. It is durable, fast-drying, and water-soluble, but it smells a little strange (the smell dissipates as it dries). Do not use if you are allergic to dairy products.
Ingredients: 2 Tbsp. casein powder; 1 Tbsp. borax, 1 oz. earth pigment
Prep time: 5 min. prep; then let sit overnight. 5 more min., and let sit an hour.