Sennelier Egg Tempera and Acrylic Gesso panelsApproveRejectUn-ApproveSubscribeUn-Unsubscribe
Question asked 2017-03-08 11:44:47 ...
Most recent comment 2020-10-20 20:13:11
Egg Tempera
Grounds / Priming
Rigid Supports
i have read the descriptions for how to make real ET paint (fairly easy) and real ET panels with rabbit skin glue and whiting (very laborious).
I cannot believe that lazy people like me who buy ET in tubes still have to make a panel. Panels with true gesso on are availale from few retailers and are expensive. Sennelier make passing reference to use on canvas with acrylic gesso, but their information is very poor.
Are you able to offer advice on using these tubed ET paints with commercially available wood panels with acrylic gesso, please?
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Moderator Answer
(brian baade)
I have used a few suppliers of panels with real chalk glue
grounds for one-three day workshops that I give and have found them quite
affordable. A quick Google search should yield a few suppliers to choose from.
Make sure to include genuine, real, or true in your search.
I cannot recommend painting egg tempera on canvas covered
with acrylic gesso. Egg tempera becomes increasingly brittle over time and it
should really only be used on a rigid support. However, tubed egg tempera paints
are always egg-oil emulsions to my knowledge. These may be slightly more
flexible than pure egg tempera. One would really need to preform tests for
adhesion and cracking. Even if the tests were positive, I would only suggest
painting your tempera very thinly and in a few layers to minimizes brittleness
and cracking,
Acrylic dispersions grounds are generally just not absorbent
enough to ensure the adhesion of egg tempera paint. Of course, not all acrylic
grounds are the same and you could experiment but I do not have good hope. As
above, the egg-oil emulsions in the tubes may fare a bit better, but I doubt
it.
As to purchased panels outside of the boutique genuine
glue-chalk grounds, I would you should test some of the better. I would test
some of the clayboards as opposed to the panels covered with acrylic “gesso”. I
know that some of the suppliers suggest that these acrylic gessoboards are
suitable as an egg tempera substrate but this has not been my experience when
used with traditional, historical egg tempera techniques. As above, however,
you should test to see if any of these fare better with the tubed egg-oil tubed
paints.
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Moderator Answer
(brian baade)
Koo, as always. Thanks for the informative post.
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Moderator Answer
(brian baade)
Thanks again Koo.
I do want to point out that egg tempera made from watercolor and egg yolk will be ever so slightly more water sensitive than pure egg tempera. This is unlikely to be a major issue, though.
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Moderator Answer
(brian baade)
Koo,
I really only mentioned the solubility issue for completeness.
The amount of gum Arabic is likely very small in proportion to the egg in
actual practice. Yes, egg yolk is an emulsion containing proteins and oils (as
well as many other components including lecithin as an emulsifier). The egg
yolk film becomes water resistant rather quickly and more so overtime. Gum Arabic
is more brittle than egg at least initially. I am less sure about the precise aspects
of the long-term aging of gum Arabic but I doubt that it becomes drastically
more brittle overtime. Again, the small percentage of the gum that would be in
the final egg tempera paint would probably not greatly change the relative
brittleness. Again, this is all just mentioned for full disclosure.
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Moderator Answer
(brian baade)
Koo,
In retrospect, I think that my answer was far less than
satisfactory. I will correspond with some individuals more familiar with the
chemistry of gum Arabic and give you a more precise answer.
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Moderator Answer
(kdeghetal)
Hi Jeremy...I have forwarded your request along to our IT point person. In short we would love to have this type of feature associated with our forum and perhaps there is a way to do it. So stay tuned.
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Moderator Answer
(koo schadler)
My experience has been that a water-soluble tempera grassa paint (i.e. a greater percentage of yolk than oil binder in the paint) needs the porosity and absorbency of a traditional gesso ground to adhere properly. A solvent-soluble tempera grassa (greater percentage of oil than yolk) adheres to acrylic gesso.
Tubed egg tempera paints are, as you note, not pure egg tempera; they are emulsions (yolk and oil binder) and, in my experience, all are water-soluble. However I don't think it would require much addition of oil paint (regardless of color) to have it switch to a solvent soluble paint. So if you make a solvent soluble paint, I believe you're okay working on acrylic gesso (although I might go for a high PVC acrylic gesso, such as Golden's Absorbent Ground, to be sure). Hopefully Brian or another conservator will chime in to confirm or counter this.
Koo Schadler
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Moderator Answer
(brian baade)
It is true that tempera formulated with a very large
percentage of oil compared to egg yolk or whole egg (technically a reverse
emulsion where the water phase is suspended in an oily phase by use of a
surfactant/emulsifier) is both diluted using organic solvents and produces a
paint that is more flexible in the long run than traditional oil in water
tempera. How much more would depend on a number of factors. None would be as
flexible as a properly formulated oil paint containing the same pigments.
These paints would also not require as absorbent of a ground
as compared to pure egg tempera. Much of this is because they would not behave
like traditional pure egg tempera. Basically, they would not use the same
application techniques which were required for successful true egg tempera
effects because they do not achieve those effects (Koo, I know that you have
shown that additional techniques are applicable pure egg tempera, but my point
still stands).
Reverse emulsion paints are, however, trickier to formulate
and tend to break the emulsion if not well made (honestly, even fatty oil-in-water
tempera emulsions can do this, especially if the binder is kept in jar unpigmented). I would not recommend painting
a fine fabric support with continuous layers of any of these paints. They would
likely be fine if applied in non-continuous layers. However, it would be far advisable
to have the fabric adhered to a ridged support.
Finally, to my knowledge, there are no pure egg yolk tempera
paints sold in tubes. They are all fatty oil-in-water tempera emulsions (what
Koo called tempera grassa).
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Moderator Answer
(koo schadler)
To clarify my response...I was focusing on the "acrylic primer" part of the question, and unthinkingly presumed linen attached to a board (I'm very habituated to working on panels). So I'm in agreement with Brian, a solid support is best.
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