Casein is a paint made from milk protein. It can be used like watercolor or like oil paint in many ways. It’s really easy and cheap to make up in the studio. Here’s a recipe for the binder that you can then mix with dry pigment to make paint.

Step one, put these ingredients into a jar that’ll hold at least 8 ounces. Stir and let sit overnight in the refrigerator.

• 2 tablespoons casein powder
• 5 tablespoons distilled water

Step two, mix these ingredients separately and add to the jar from step one.

• 1 tablespoon borax. You can find this in the laundry section of the grocery store.
• 3 ounces hot distilled water

Let this stand, at room temperature, for about 8 hours. This will give you a casein glue. You can mix this with water, about 1 part glue to 1 or 2 parts water, to make a binder for your pigment. You can stir it up with pigments on the palette or make up small quantities in a jar.

Casein is not as flexible as oil paint so you’ll want to paint on a rigid surface. I like gessoed panels or paper mounted to panel.

One can make a casein ground although I find hide glue better.

This recipe is adapted from D.B. Clemons. I find that his water ratio in the binder is too high, resulting in an underbound paint film.

Here’s a similar recipe from Sinopia.