Casein paint
Casein paint, derived from milk, is a fast-drying, water-soluble medium used by artists. It generally has a glue-like consistency, but can be thinned with water to the degree that fits a particular artist's style and desired result. It can be used on canvas panels, illustration boards, paper, wood and masonite. Casein paint is reworkable and can be used for underpainting. It generally dries to a matte finish. It has an important place in the heart of artists. It's almost same as gouche as an opaque water based medium when dried produces a beautiful matte finish.Casein paint can be used as fast-drying underpanting for oil glazes, or mixed with other mediums. While using casein we must be carefull because it becomes breakable when dry.
Casein paint is simpler to correct than oils. This is because the paint dries quickly and is suitable for three dimensional forms. This is more easier and convenient to work with than oils. Casein paint has been used since ancient Egyptian times as an alternative to tempera paint, and is still used today.