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arbrador 24-12-15 06:09 PM

More on casein gesso
Hi All~
Many years ago I tried casein gesso because I liked the idea of not having to use warm gesso and wrestling with air bubbles. I can't remember why I did not pursue it but remember that I did not like the surface as much as traditional gesso.

Recently Elaine Drew tried the Sinopia version and also was not happy. Here is her summary:

"Mostly, it seems the paint doesn't adhere well to the surface. I did a couple of pieces that came out all right, eventually, but the paint sliding off was annoying. After enough layers were built up it seemed to be better. I also had a problem doing an ink underpainting; that slid off as well."

She did extensive experiments at the time including using traditional gesso over a couple of coats of casein gesso but in the end abandoned the whole idea of using casein gesso.

At least now we can buy our smaller panels at a reasonable price. My problem it I'm painting larger and larger ETs and there's no way I can afford to buy a gesso panel that is, for example, 4'x8'. So back to the meditation of traditional gesso.

Koo Schadler 25-12-15 03:58 PM

Thanks for describing Elaine Drew's experience, Lora. At the risk of redundancy, but for the sake of ET newcomers, I'll point out that Elaine is an accomplished tempera painter who, from past experience, was able to recognize the distinction between the working properties of traditional gesso and casein gesso. A newcomer to the medium wouldn't know that the casein gesso wasn't behaving optimally for egg tempera, and might assume that slipping paint is intrinsic to tempera (or the fault of the painter). That is the problem with new grounds that are advertised as ideal for tempera - they mislead the beginner. Which is why, much as I like Sinopia as a company and think their products are generally great, I'm being a bit of a pest here regarding casein gesso; my persistence come from advocacy for egg tempera.

No doubt, making gesso from scratch is work, particularly a large panel. To clarify (again, primarily for beginner's sake) there are ways to mitigate and/or eliminate air bubbles: minimize agitating the gesso while making it, let prepared gesso sit in the fridge for a day or two (so it can settle down) before application, add a flow aid to the gesso, don't overheat the gesso (keep it just warm enough to stay liquid), don't have too much of a temperature difference between the panel and gesso, be attentive as you build layers, etc...

Whatever the work involved, keep in mind the benefits: As Lora points out, it is a thoughtful, meditative process. It makes you more knowledgeable of your materials and process (which, if not certainly, can potentially make you a more attentive, better painter). These are increasingly less common but perhaps worthwhile experiences. Understandably, they are not for everyone - but we tempera-philes already knew that about our medium!

I admire you following a call to paint large, Lora - I'm working on a 14 x 18" triptych and it feels like my limit (well, at least for now, maybe forever). The Death of Jack Walsh on your website is a beautiful painting. Congratulations on persisting in the challenges of a medium I know you love.


dbclemons 01-01-16 03:19 PM

I want to be sure everyone's aware that there is a distinction to be made for the term "Casein gesso." You can make it using casein as a substitute for rabbit skin glue in the traditional manner. Sinopia sells all the raw materials to make it that way. They also sell this casein gesso product which is NOT the same thing. It is an oil primer that uses casein as an emulsion. I've been making true casein gesso for many years, and prefer it over RSG, mostly for the sake of convenience, but also for the results I get.

Koo Schadler 06-01-16 01:40 PM

Excellent point, DB - thanks for clarifying.


Koo Schadler 15-11-17 06:59 PM

Hello All,

As discussed in this thread, several years ago Sinopia (an art supply company in San Francisco) developed two new grounds advertised as suitable for egg tempera: casein gesso and chalk casein gesso. Both products have the convenience of being pre-made, ready to apply. I tested the chalk casein gesso and, for me, it didn't behave well; paint lifted, it was hard to quickly accumulate layers without lifting, very watery applications of paint took a long time to dry. I wrote about it in this post and recommended against Sinopia's chalk casein gesso for egg tempera.

Leslie Watts, a well known egg tempera painter, recently tried both of Sinopia's casein grounds and found them to behave well. She wrote about them in a blog post. Everyone has different working methods, and what may not suit one painter may work perfectly well for another, so it seemed only fair to offer a differing opinion on these grounds. A link to Watt's post is below.

Koo Schadler

dbclemons 21-11-17 04:32 PM

Thanks for the link, Koo. I appreciate hearing about your experiences with their two grounds. It's worth mentioning that both of these Sinopia grounds are made with the same binder using casein with oil and resin. The chalk ground includes extra pigments titanium and zinc.

On your point about different working methods, can you add more detail on what methods could be leading to these different results? Have you worked on grounds with any oil content before? I'm wondering if that may be what's causing you difficulty.

Koo Schadler 25-11-17 07:54 PM

Hi DB,

I have worked on oil based grounds, but only when painting in oil. There seems to me a fundamental incompatibility between a ground that contains (even a very small amount) of oil, which is water-phobic; and a water-based medium, such as egg tempera - especially if controlling and getting the water in ET paint off the surface asap (by having it be absorbed by the ground) helps in controlling the paint.

If a tempera painter has a working method that uses absolutely minimal water - i.e. very dry brush - than that painter probably can get an oil-based ground to behave. I work a lot with dry brush in egg tempera, but I also work with puddles of paint, thick sponged-on layers, wet splatterings, and other water-intensive ways. Additionally I accumulate a lot of layers, anywhere from 20 to 200, often quickly, depending on what I'm painting (and the more layers, no matter how they're applied, the more water is introduced into the ground).

Another consideration is brushwork. Crosshatching (how many ET painters work) helps weave together the paint; and a single, thin brushstroke is less likely to lift or affect areas of previously applied paint. I don't do a lot of crosshatching. I apply more random mark-making, as well as continuous layers of paint. Continuous paint layers are less interwoven, and their application is more likely to wet and thus affect larger areas of a painting, which potentially creates more opportunities for lifting (if the water has no place to go).

All these things are probably why my working method is not well suited to a ground with oil in it. Egg tempera (unlike oil) can't be physically pushed around or blended on the surface; instead ET painters create an image by (a) controlling the sort of marks being made, and (b) accumulating layers. These two things are possible only if a painter has control of the water content in the paint, and a maximally absorbent ground helps to do this.

If you have any thoughts on the above, I'd be most interested. Also, if you've had experience with any of the alternative gessos, please share. It's good to hear your voice on the forum.


dbclemons 02-12-17 03:59 PM

Thanks, Koo. I appreciate the information.

I made some simple tests with e.t, casein, oil, and gouache paints on this, and they all seemed to adhere well, but haven't yet tried anything advanced with them on this surface. Honestly, I tend to avoid using a primer unless I'm painting with oils, which I haven't used in awhile.

As I mentioned in my own review of this, I wouldn't describe this as a gesso. It's an oil primer with a casein emulsion that makes it water-miscible. It makes sense that if you use a paint on it that is heavy with water, that can be problematic. If anything that is touted as being more convenient to use forces you to have to alter your preferred method of working, then it isn't really worth using, in my opinion. I still have a little bit left in the jar, so I may get around to doing more work with it later.

One last observation I made: it comes in a plastic jar with a screw-on lid. One big reason I dislike using jars (glass or plastic) of this sort to store mediums is they tend to let air leak in. This jar was no different. When I opened it recently I found about a third of the contents at the top had dried solid, even though the lid was screwed on tight. If anyone buys some of this, be sure and use it up quickly.

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