Casein (kay'seen) paint is derived from a milk protein, is a fast-drying, water-soluble mediums. It is applied to a rigid surface like wood and has a matte finish.
Like Encaustic, Casein is an ancient painting method. Ancient Egypt paints made of milk and pigments. Recipes for the use of adhesives made from Casein, or curd, date back to the 11th century.
I started using casein as an underpainting for some of my encaustics in 2020 and have enjoyed it so much I started to paint some small casein paintings. My casein paintings are coated with encaustic to preserve surface and give it a gloss.