Casein paint is not as well known today as is acrylics or watercolor. It’s an ancient type of paint, derived from milk protein. It’s fast-drying, and water-soluble. Once dry, the paint becomes water resistant to a large degree. This allows for building in layers as you would with acrylics or oils. The finish is matte and a bit chalky, unlike the shiny surface of acrylics. Casein has been used for both portraits and murals since the late 19th and early 20th centuries.
One advantage to this type of paint is that it can create effects similar to oil paintings. It permits the use of bristle brushes and a moderate impasto. However, unlike oils, it doesn’t create a fusion of tones. Casein paintings may be varnished to further resemble oils and can be glazed or overpainted with oil colors.
Because casein is too brittle for canvas, it is best applied to rigid boards or panels.
Here are some tips for working with casein from personal experience.
Casein tip # 1 — When painting in casein NEVER dip your brush into dirty water and then mix white. This leads to muddy whites. Instead, dip your brush into clean water before ever touching wet white paint. That will make your colors much better, and brighter.
Casein tip #2 — When applied too heavily, casein can start to flake off the page. Work in thin layers and don’t let the build-up of paint become too heavy on the surface.
Casein tip #3 — Casein can create vibrant underpaintings. Choose a warm or cool color, say yellow ochre or a cool blue, let dry, then try painting over it with watercolor or gouache. The color will show through and can provide some lovely effects. (The girl in the painting shown here was underpainted with the same dark orange you see in the background.)
Casein tip #4 — Casein is hard on your brushes. Wash them out with mild soap and water after each painting session.
Casein tip #5 — Unlike watercolor, casein does not perform as well when re-wet. At the start of each painting session squeeze fresh paint out of the tube. If you want to save paint at the end of the day, try wetting the remaining of paint on your palette with a spray bottle then cover with plastic wrap for the night. (I use a Masterson Sta-Wet airtight palette when I am doing a painting that will take more than one day to complete.)
Do you use casein? What do you think of it? Comment below.