Feel free to ask your questions here as well.

Barb, it might help first if we look at why a varnish is used on any sort of painting. The paint surface can collect dust, grime, smoke stains, etc. over time, and a varnish layer can offer protection for cleaning so that the paint surface itself is not touched. Some pigments can also have more of a matte or gloss tone when they dry, and a varnish resin can help balance that out over the whole painting. There are different sorts of varnishes, but they all offer more or less the same results, They can be matte or glossy, temporary or permanent. The most practical type of varnish in terms of conservation care is one that can be removed if it becomes damaged or discolored over time.

Regarding casein or any other similar paint surface that is somewhat fragile, if you apply a varnish to it, the varnish automatically becomes permanent since there’s no way to safely remove it later on without removing paint. If the varnish ages poorly, there’s nothing you can do to fix it. Another problem is that the casein surface can absorb the resin in such a way that it actually changes the coloring and value of the pigment, depending on how the paint was applied, thus changing the look of your painting, perhaps for the worse. I have found that if you wait several months (3-4) for the casein to cure completely, that is less likely to happen than if you varnish earlier. Spirit or oil varnishes tend to work better in that case than water soluble varnishes that might disturb the casein layer.

In the absence of a varnish, glazing (glass or plexiglass) can be used to protect the paint surface. This is the most convenient solution, but it can add to the overall weight and fragile nature of the work, glare or non-glare issues, costs, etc. If you’re exhibiting a work on paper some places demand that paper pieces be behind glass. It also doesn’t help solve the patchy gloss to matte paint surface problems.

In the end as a general rule, most will advise you to hang casein under glass, and that’s what I often do. After it has cured (if I still have it,) I may add a varnish so that glass is not necessary. Otherwise I would just keep it in storage so it dosen’t get dirty.

Hi John
I’m glad you have decided to join Wet Canvas. I will have a lot of questions for you about using casein.

I have read many references that say you should not paint casein on canvas. Is this correct? How do you get around this problem?

What is the best support for painting casein?

Thanks
Alex

Wow!!! John, thank you!!!

Is [URL=http://www.johnmolnarpaintings.com/]this[/URL] you?

Jan

I guess that IS you, John.

Jan

Hi alexs,

I have painted casein on canvas for 25 years or so.
This is emulsified casein, that is casein tempered with oil.
The brand I use is Shiva Casein.
The references you have read probably relate to untempered casein, or “milk paint’, or lime casein.
I paint in thin layers, and build them up in layers.
I have some examples of mu casein paintings at my website: [url]http://www.johnmolnarpaintings.com/[/url]

Painting with casein is much like painting with gouache, only it dries into a polymer,(film or skin) onto gessoed canvas.

Please write to me with any more questions or ideas you have about casein.
My email is [email][email protected][/email]

John, I use the Shiva casein too. I didn’t realize it was different from other casein paints. I assume you’re saying that it is already “tempered” with oil? Why does it dry so quickly then?

Do you use stretched canvas, or canvas mounted to a stiff support like hardboard? I think I’d worry about cracking on a very flexible support.

Jamie

Can you mix watercolor paints, from a tube, with the casein emulsion to get a different color. I didn’t want to go through the expense of buying dry pigments just yet.

I still would like to go through with the exercise of mounting my casein paintings on masonite. The paper has several coatings of acrylic gesso on the front and back prior to the casein application. I intend to apply GAC 100 to the masonite and then apply an acrylic gel medium before mounting the casein painting. Would this be a reasonable approach?

I have tried mounting the casein painting on acid free matboard. The matboard warps.

Alex