Friday, May 26, 2017

Casein Emulsion and Varnish

Julien from France asks:
"I've finally bought Richeson casein online, still quite expensive [to import to Europe], but quite cool, actually different from gouache or Holbein's Acryla Gouache. My question is, have you used the Shiva casein emulsion or varnish, and can you use it with gouache?

First, a little background. For those who don't know, when you buy the emulsion separate from the paint, you're getting the liquid glue-like binder that holds the pigment together. Casein emulsion is a water-soluble, milk-based protein in liquid form in a can or jar. It's the same stuff that they use to formulate the paint.

Shiva is the company that originally made casein paint. The company was bought by the Jack Richeson company, which markets the product under both the Shiva name and Richeson brand, but I believe they're the same product.

Detail of Skysweepers, painted with gouache with some acrylic medium

In answer to your question, I have only experimented a little with the casein emulsion. I don't see any reason why you can't use casein emulsion with gouache. It would make gouache behave more like casein. You could even use acrylic medium with gouache. I used to do that a lot, because I liked the opacity of gouache, but I wanted it to have the sealed surface of acrylic.

I have used the casein varnish made by Richeson, which is a liquid brush-on varnish. As far as I know, they no longer make it. I found that it doesn't work well with watercolor paper because the paper is so absorbent. It just soaks the varnish up, so it requires a lot of coats before you start getting a gloss.

But on a panel, the varnish develops gloss with just one or two coats. The varnish is helpful for bringing out the depth and richness of dark paintings. If you're using paint with a matte surface, dark passages are prone to looking chalky. I find that the matte surface of gouache or casein is better suited to more high-key palettes.

If you want to varnish a gouache or casein painting, you could use a spray varnish, but keep in mind that once you apply a varnish, the surface is closed, and you wouldn't want to paint over it again with either casein or gouache.

7 comments:

gyrusdentus said...

is there a reason why you do not opt for acrylic when wanting opacity,shine or no shine and layering?

Terry Stanley, The Art Lady said...

Hi Jim - Terry here putting in my unsolicited 2 cents of knowledge from my years at Richesons. Richeson Shiva Series caseins are indeed one single product line. Emulsion info: Actually is to be used to make your own casein with pigment, mixing the emulsion as you do with egg tempera, then thin with water. Some people will use the emulsion as a medium and it's fine to do that except you 1) may extend drying time and 2) will lose the lovely matte finish of the paint, which is why casein was so prized by illustrators - the matte finish reproduces beautifully. Casein shouldn't be varnished (or finish of some sort be applied) before it is completely cured, which can take up to 4-5 weeks. Varnish is actually unnecessary which is why it's not made anymore. If you insist on varnishing, an acrylic one will be fine. Do NOT use an oil varnish as it can cause adhesion issues, orange peeling, etc. Casein on panel or other rigid support is meant to be buffed. Once completely cured, take an old t-shirt rag or other non-listing cloth and gently but vigorously rub the surface. A lovely satin-ish sheen will come to the surface and actually protect the painting. Properly applied to an acceptable, prepared painting surface, caseins weather time even better than oils. If you use paper as your chosen surface, it is recommended that it be framed under glass.

James Gurney said...

Thanks, Terry, that's all very helpful info. I've noticed that the cure strength of casein really increases day by day after it dries. I remember you told me about buffing, and it's a great solution, giving kind of a soft sheen without too much gloss.

Gyrus, I actually like weaker emulsion strength for opaque painting, plus the ability to reactivate the surface of gouache. However, I do use acrylic, especially for painting maquettes.

Daniele Guadagnolo said...

Hi, Terry, thank you for these insight about casein painting.
What would you suggest as a rigid support for casein? As I previously stated here on GJ, I tried painting on an acrylic gesso primed panel but did't like the surface. The first layer felt very slick, and it also reactivated very easily compared to works on paper.

Biff said...

I have had instances where casein comes out of the tube too dry. In that case I have successfully mixed in a little casein emulsion. I have also found it effective to transfer the emulsion from the original large jar container to little "GoToob" squeeze bottles which makes it more portable and prevents it from drying out in a container. If you fill up the GoToob initially, air doesn't get in as you use it (the GoToob has a little flap valve) so the emulsion stays fresh.

Bekah said...

Thanks for your info about casein. I find that using the Richeson Shiva Casein Emulsion (ratio 1:5 medium to water as recommended) instead of just water to control the casein paint is working quite well, as it both thins the paint for the effects I want and slows the drying time just enough to not be blotchy in a wash. When it's watered down this much it does not make the casein shiny. I thought I'd share that the MITRA forum has a casein category, and the moderators have been helpful in answering my questions. Here's a link: https://www.artcons.udel.edu/mitra/forums/question?QID=415

AkMAP said...

Thank you Terry for the tip about buffing! My process may have a surface too rough, or I may need to grind more. And thanks Bekah for the link to the site. I found this blog while looking for artists that use Casein. With Casein, I'm not getting quite the results I can get with acrylic. I'm a hobbyist with watercolor, acrylic, and pastel. But, I encourage everyone to try making their own Casein!
I've been playing with making casein for a couple of years. I've used a variety of recipes. But borax (mixed with water just to the point of suspension -no grit) and a milk protein with slaked lime (only available in a 50lb bag) is all you need. I keep the borax mixed with water in a kitchen squirt bottle and I just squirt a pile of milk protein (powder,cheese, etc.) on a plate. I make it a little thicker than the consistency I want because the pigments I use are in water. I mix it until smooth with a palette knife. I may switch to a pestle and mortar. For the milk protein I've used finely powdered milk (not Carnation- grainy), whey from milk made with vinegar (messy), cottage cheese, or most recently, ricotta cheese. I add a little slaked lime (in a half cup of mixed casein I add a teaspoon or less of the lime. I buy pigments suspended in water. They can be more finely ground in the water by the manufacturer and you don't have to deal with hazardous dust. Some of those heavy metals are rather hazardous, even cancerous, when inhaled. Shipping the liquid is expensive and that titanium white weighs a lot! http://www.guerrapaint.com/
I just went back to a painting I created a couple of years ago on a gessoed, masonite panel and it is SOLID. The new touch up paint I wanted to apply sort of beaded up. The stuff seems waterproof. I had read that the Quakers used it for painting everything, even outdoor stuff.
I am trying to use it because of environmental considerations (Anchorage is on an EPA waiver and after removing the solids from our waste, everything goes into our Inlet (and anyone wonders why the Beluga whales are in decline?). Also I wanted the purity of color. It has few additives, mostly only pigment.
When I mix it up, it's only usable for the day, maybe a little longer if I put it in a small airtight container. I like to use it on the cheap acrylic paper, it's plastic coated I think. I have used it on prepared panels and I have used it on canvas panels. I will stay away from any type of canvas from now on. I have a tendency to make it too thick and it cracks. On the masonite, gessoed panel, I've come back to it days later and have been able to squirt it with the Borax solution and scrub most all of it off the panel and start over! I haven't tried that on something that's set for a long time. The Casein is easy to make and the process reminds me of Sumi e. The work required to get it ready, grinding to make it smooth, can be used as a meditation time, a time to reflect about the painting about to be made.