Lines and Colors art blog

Painting with casein, Samuel Coleman, John Molnar, unknown ancient Egyptian artist, Harry Anderson, Gustav Klimt, Jane Fisher, Len Guggenberger, John Berkey, Walker Moore, David S. Costanzo, Anthony Martino, James Gurney, Henri de Toulouse-Lautrec, Alan Bray, George Mclean, Colin Campbell Cooper
Casein (pronounced “kay’ seen”) is a water based paint in which the binder is the milk protein of the same name.

Casein is one of the least familiar of the water based painting mediums available to contemporary painters, even though it’s one of the oldest painting mediums known. Casein’s use can be reliably traced back over 9,000 years, with evidence of the formulation in cave paintings, and examples have been found in ancient Egyptian tombs from several thousand years ago.

There is new evidence that casein as a binder for paints may have been present in the oldest known examples of human use of painting materials, recently analyzed traces preserved in caves in South Africa from 49,000 years ago. (For reference, the oldest known examples of human writing — i.e. language, not just numbers — are only about 5,000 years old.)

Casein has a varied history, frequently used as an underpainting for oils and achieving its greatest modern popularity as a stand-alone medium in the mid 20th century, when it was popular with illustrators for its quick drying time, workability and easy-to-photograph matte surface. Like its gum arabic based cousin, gouache, the use of casein by illustrators was largely eclipsed by acrylic, which quickly dries impervious to water and subsequent applications of paint layers.

Casein has been in use as a decorative paint for furniture and other items, where is is generally referred to as “milk-based paint”; I’m not sure if the formulation is different from the artists’ paint. Casein has also been used as a ground for oil paints and for silverpoint drawing; the binder itself is a glue, used in undiluted form to glue furniture.

Casein has an interesting place in the spectrum of artists’ paints. It most closely resembles gouache as an opaque water based medium that dries to a beautiful matte finish. Like gouache, it changes value somewhat — generally lightening — as it dries. This can take a little getting used to and it can take multiple layers to produce satisfactory darks, but I find that more than offset by casein’s other qualities.

Casein is more full-bodied than gouache, and can be used a bit more thickly (though not in heavy impastos like oil). This makes it a little more like oil in terms of scumbling and creating interesting surface textures, and it can be particularly appealing to oil painters who want the speed and convenience of an alternative water based medium.

Casein also has a particularly nice characteristic of flowing off the brush, and can be applied to a smooth and even flat color surface, much like gouache.

Some have said they’re not fond of the scent of casein paint, but others, including myself, find it quite pleasant. Your mileage may vary.

Unlike gouache and watercolor, which can always be reactivated with water (either an advantage or disadvantage, depending on the artist’s needs), casein eventually dries to a surface more resistant to water.

Varnish can be applied to paintings that have dried for two weeks or so, either matte or glossy, the latter application bringing out the darks and giving the painting a look closer to oils. Care must be taken, though, not to disturb the surface when applying the varnish; and spray varnish is often recommended. You’ll find more detailed information on some of the sites I’ll list below.

Like gouache, casein is being “rediscovered” by contemporary artists, and appreciated for its unique characteristics. It is particularly suited, I think, for plein air painting.

“True” casein must be made up frequently by the artist, as it goes off in a day, or 4 or 5 if refrigerated.

Modern adoption has been greatly boosted by the availability of casein emulsion, a formulation of casein and drying oil that does not readily spoil and is available in tubes.

To make “true” casein, vinegar is used to separate out the liquid whey, leaving the curdled milk protein — essentially cottage cheese. This is dried and ground to a powder for future use or used immediately, and usually mixed with water and ammonium carbonate or clear liquid ammonia (though there are other formulations using lime or borax). The result is a milky fluid into which powdered pigments are mixed to make paint.

Already extracted and dried casein powder can be purchased from suppliers like Sinopia, Kama Pigments or Earth Pigments (recipe here).

The tube casein seems to have most of the wonderful working qualities and beautiful surface appearance of the fresh made version, and is certainly an easier approach to the medium.

Casein emulsion tube paint

Jack Richeson & Co. is the most prominent provider of commercial casein paints, having bought the “Shiva” line and name from the previous manufacturer. Their casein emulsion paints are available through the majopr online art supply houses, though I understand that they may be difficult to find outside the U.S.

Plaka, by Pelican, is another brand of casein based paint, that I know is at least available in the UK, though it may be aimed somewhat more at decorative artists than painters.

Casein is generally less expensive that gouache, perhaps because the binder and formulation of pigment is less costly, I don’t know. It comes in large tubes of 37ml, similar to oil, as opposed to the small tubes favored for watercolor and gouache.

Casein, like gouache, is brittle when it dries, and if used thickly, should be used on a heavy watercolor paper, or ideally on illustration board or panel. Ampersand, which makes familiar painting panels for plein air artists, makes a line of Claybord, that they promote as being ideal for casein and gouache, largely because the clay infused primer is absorbent, in contrast to the non-absorbent surfaces of acrylic primer (“gesso”) favored for oil painting. I’ve also been working successfully on 140lb watercolor blocks and hot press Bainbridge Board (I use hot press because I prefer a smooth surface).

To a point, casein washes up like watercolor or gouache, but because it hardens to a water resistant form over time, more care must be taken to wash out brushes after painting, or keep them suspended in a brush washer. Casein is also a little rougher on brushes than watercolor or gouache, and like gouache and acrylic, it’s considered preferable to use synthetics. Because of the thickness of the paint compared with watercolor, casein painters often use brushes labeled for acrylic, somewhere in between stiffer oil brushes and softer watercolor brushes.

It can also be a little more difficult to get brushes clean, I use a little Murphy’s Oil Soap, I’ve also heard Greek olive oil soap recommended.

Casein is well suited to be used with gouache, the former giving body and texture, and the latter being even better for fine detail and sharp lines (though casein does well on its own in that respect).

Casein is often used with other paints, notably acrylic, in which acrylic plays the role of thin, transparent application and casein provides the ability to easily create thick, opaque passages — similar to the way watercolor and gouache are often used together.

There is a National Society for Painters in Casein and Acrylic, which sounds promising, but the navigation in their online galleries of competition winners is so terrible as to be almost unusable. You have to click to enlarge an image in a pop-up just to see the artist’s name, and even then there is no indication of the medium. You have to either look up each artist in Google and go to their own sites to look for the medium, or look for the winners of the “Richeson/Shiva Award For Casein Painting” as you wearily pop-up and close, pop-up and close, pop-up and close, in an attempt to find the few casein painters among the predominant majority of acrylic artists. Unfortunate; it might otherwise be a good resource.

Also unfortunate, and similar to gouache, is the dearth of information on casein use and painting techniques compared to other painting mediums. The Richeson site provides some information, and you can find casein mentioned in art materials compendiums, like Mark David Gottsegen’s The Painter’s Handbook, as well as in older books on illustration materials, like Rob Howard’s The Illustrator’s Bible.

A number of artists who work in casein feature short informational pages about the medium on their websites, and I’ll list some in my links, below. By far the best source I know of is James Gurney’s blog, Gurney Journey.

Gurney has for several years been working with casein, as well as gouache and other mediums, and has been sharing his experience and findings in the form of articles and short videos.

He has just released a new full-length instructional video, Casein Painting in the Wild, which I cover in a separate post.

One of the segments of his video demonstrates painting in a very limited palette of four colors, and artists who are curious about casein may want to try a similar approach to simply try out the medium.

Personally, I find casein to be a genuine pleasure to work with. I like the way it flows and handles, the textural possibilities and the appealing color and matte surface in finished paintings.

Artists who try it may be surprised at how nice it can be to work with.

Cave walls optional.

[Addendum: David Clemons, who has painted in casein for many years, has been kind enough to add some additional information. Please see this post’s comments.]

(Images above, links to my posts: Samuel Coleman, John Molnar, unknown ancient Egyptian artist, Harry Anderson, Gustav Klimt, Jane Fisher, Len Guggenberger, John Berkey, Larry Seiler, Walker Moore, David S. Costanzo, Anthony Martino, James Gurney, Henri de Toulouse-Lautrec, Alan Bray, George Mclean, Colin Campbell Cooper)


18 responses to “Painting with casein paint”

  1. Great summary, Charley, and plenty of new information. It’s fun to be a champion of a forgotten medium. Anyone who picks up casein automatically becomes a Possessor of Secret Knowledge—like playing the crumhorn or touching up a Rubylith. We should be issued special embroidered patches to adorn our painting jackets.

    1. Thanks, James. I like the idea of a Possessor of Secret Knowledge patch, perhaps with a chemical formula for milk protein and ammonia!

  2. Thanks so much for the posts on casein painting — I’m a huge proponent of keeping alive traditional arts such as these. Tatting, a method of lace-making, is experiencing a similar sort of crisis but through efforts like yours and those of James Gurney I know casein painting (and hopefully gouache, too) will see a resurgence in popularity.

    1. Thanks, Brandi. I think the preservation of these skills is one of the great benefits of internet based communication. Interested individuals can connect and share information much more easily than in the past.

  3. Charley,
    Thank you for taking the time to write such a thorough article about casein.
    I have vey limited experience with the medium, but have been greatly inspired by both you, and James, to give it a more serious exploration (adding credence to your statement about the “benefits of internet based communication”).


    1. Thanks, Bill. There is a versatile limited palette I favor that works in casein as well as gouache or oil, and is only 5 paints: Ultramarine Blue, Cadmium Yellow Light, Alizarin Crimson, Burnt Sienna and white. You may have seen my previous article on this limited palette.

  4. JD Roland Avatar
    JD Roland

    Mr. Parker;
    Thank you for such a thorough and interesting article. I cannot tell you how much I’ve enjoyed your beautiful site, especially this past year. Every evening, I sit down with happy anticipation to see what you’ve uncovered next. Sometimes getting lost in the beauty of your choices seems to be the only peaceful hour of my day. Thank you for all of your time and research-I know it must be a lot of effort.
    With gratitude and respect-
    JD Roland

    1. JD,
      Thank you for the nice comment. Yes, I do put some effort into research and trying to make my information accurate and informative, and I appreciate knowing that my articles are being enjoyed. I’m also always happy to know I’ve introduced someone to new artistic discoveries.

  5. Thanks for an informative article with new info for those of us experimenting with casein paint. I’ve been using it for a few weeks now, inspired by the postings by James Gurney, and put a handful on my blog.

  6. Thanks for an informative article with new info for those of us experimenting with casein paint. I’ve been using it for a few weeks now, inspired by the postings by James Gurney, and put a handful on my blog.

  7. A very nice article, Charlie. I’d like to add a few things based on my own experiences with casein. I’ve been using it for decades, and it’s one of my most favorite mediums.

    Casein is an oil emulsifier, meaning it can be mixed with oil paint or mediums, just like egg. Any techniques or applications that use egg and oil can have casein as a substitute. For example, you can thin oil paint with a wet casein mixture to use for undertones instead of using oil solvents that have ventilation issues.

    Casein also can be substituted for rabbit skin glue to make gesso. Unlike rsg, it doesn’t require heating.

    “Milk paints” that I see online typically use lime as the catalyst to convert the casein into a binder. This can be a problem with some pigments. They also tend to only make “pastel” colors with white pigment mixed in.

    I’ve never had a problem of any kind with brushes. I suppose if I left the paint on there for a week or more, but why would I do that?

    I make my own casein paint and medium, which is extremely simple. I don’t have any trouble with spoilage since I add a drop of preservative, usually thymol. This is what gives the binder an odor. The preservative would extend the life almost indefinitely, not requiring refrigeration. This is what Richeson does to the medium they sell commercially; although, I don’t know what type of preservative they use. It doesn’t so much spoil as lose its binding properties after a long period of time. As such, I typically make only about 8 ounces or so at a time. Without a preservative, casein is essentially cheese, so you’d have to treat it accordingly.

    About varnishing, I usually wait about 3 to 4 months. At this point the casein has completely cured and is water resistant. I proceed as I would varnishing an acrylic painting by first applying an isolation medium. My preference is Liquitex Medium & Varnish. This will permanently protect the casein beneath so that I can apply any acrylic-safe varnish on top that could be removed if necessary without affecting the paint.

    I’ve recently been experimenting with casein as a spray fixative with very good results.

    1. Thanks, David. Very helpful. I’ve added a mention of your comments to the post. For the benefit of other readers, you can find additional information on the D.B. Clemons website, in the form of several articles about casein paint.

  8. Thank you, Charlie.

  9. Philippe Briand Avatar
    Philippe Briand


    Very interesting discussion, it is hard to find information about casein.
    I use it in a very limited fashion to seal the wood of violins prior to varnishing, it also hardens the plates as well as isolate the wood…
    I just wanted to add that one can speed up the making of casein paint if in a hurry by not soaking the casein powder overnight in cold water but by just adding a few drops of strong ammonia to the casein powder/water mix. It will dissolve in a few seconds.

    Thank you for all the info and shared knowledge.

    1. Thanks for the comments, interesting information and the added tip, Philippe!

  10. Douglas McKenzie Avatar
    Douglas McKenzie

    Would like to try casein and compare with acrylics and oil.

  11. Thanks so much for the info. FYI: I asked the moderators at the MITRA site about mixing casein with oil paint, and they strongly recommend against it, for the reasons given in the following link. I note that I’m using Richeson casein tube paint, not making my own casein paint.

    1. Thanks, Bekah. It’s an interesting read. My personal tendency would not be to combine casein with other paints as much as to use it as an underpainting or imprimatura over which I might use oil or gouache once the casein had dried long enough to be resistant to water.