Viewing Topic "Egg Tempera Impasto"
You can try heat setting on Ceracolors that is applied over egg tempera, but if you use heat apply at the lowest heat possible.
"To avoid certain issues in combinging the two mediums in a single paint layer, why not use Ceracolors over egg tempera?"
Thanks George, that is definitely what I will be doing! When using Ceracolors over egg tempera, do I need to take any precautions when "heat-setting" the Ceracolors? I have the option of using a heat gun or a hairdryer - I just wanted to see what you might recommend for this step. Thank you!
In answer to your questions regarding the use of Ceracolors in layer, the fat over lean rule does not apply here. To avoid certain issues in combinging the two mediums in a single paint layer, why not use Ceracolors over egg tempera?
Thank you Koo for the tremendous amount of information and insight you've shared here! I can't wait to try the simple emulsion recipe you suggested. It sounds divine. I will definitely be keeping an eye out for the results of your test, and will surely do some of my own.
Also, many thanks to you George for your reply. I have done a few little studies in egg tempera now, in which I used Ceracolors as the final layer to build texture (as you suggested) and they look fantastic. I know only time will tell how the two different mediums will age, but for now they seem to pair very nicely.
With regards to the various impasto tests that Koo listed: would you say at it's a good rule of thumb to think of all of these as techniques for the final/"finishing" layer(s) only? Being a novice at egg tempera, my guess would be that once oil or wax (Ceracolors) is introduced, the subsequent layers should contain the same or greater amounts of oil or wax (fat over lean)? Thank you both for your time and interest in this topic. It's a great help to me!
In item 2 you may want to try colors and mediums separately as the formulation of the wax emulsion is slightly different in each. Otherwise, I think the list is good.
To clarify, here's what I'm thinking of testing.
The quality of the impasto of the following on top of egg tempera:
1. Pure Egg Tempera in a buttery, semi-impasto form (as described in my first post)
2. Egg Tempera with Ceracolors added (either Ceracolor paint itself, and/or Ceracolor medium or paste - maybe all? What do you think, George?)
3. Tempera Grassa
4. Tempera Grassa with Ceracolor added
5. Tempera Grassa with Oleogel added
Your input is of course welcome.
Let me clarify what you've written above: You will test 1) egg tempera with Ceracolors added; 2) Ceracolors over egg tempera (dried); 3) tempera grassa with Ceracolors added; 4) tempera grassa with Oleogel added. Is that correct?
I'll do a test panel of different impastos on top of egg tempera, to include: pure tempera in a thickened form (as described in my initial post); ET with ceracolors added:ceracolors: tempera grassa; tempera grassa with Oleogel added. Any other ideas?
Not sure when I'll get to it, but I'll let you know how it turns out.
Rather than adding Ceracolors and/or Ceracolors mediums to egg tempera, why not simply build texture with Ceracolors over egg tempera painitng, much like some artists do with oil painting on egg tempera?
I doubt the wax in Ceracolors contributes any degree of flexibility to layers of egg tempera. It would certainly alter the characteristics of egg tempera.
Wax doesn’t polymerize, egg yolk does, so the question is whether the addition of wax might interfere in any way with the curing of tempera paint. The process of egg yolk polymerization hasn't been studied as comprehensively as, for example oil, and I don’t believe it is in fact fully understood yet. In my quest to better understand yolk polymerization, conservators have recommended a couple of papers to me – but they are dense scientific writings, I don’t completely understand them. If you want to take a crack at them, they are:
1. Comparison of oil and egg tempera paint systems using time-of-flight secondary ion mass spectrometry by Zachary E. Voras1, Kristin deGhetaldi, Brian Baade, Eric Gordon, Glenn Gates, Thomas P. Beebe1
2. Molecular Aspects of Mobile and Stationary Phases in Ageing Tempera and Oil Paint Films by Jaap Boon and others.
Anyhow, it does seem logical that if you can add ceracolors to other water based paints successfully, you could do so with tempera – it might work wonderfully; then again, art supplies can be full of surprises. I don’t know if anyone knows for sure the long-term results of this combination (if someone does, please chime in!).
I believe egg yolk polymerizes within about 3 months (maybe 6 months, tops). So it wouldn’t be too long term of an experiment to add ceracolors to some tempera paint and see what happens. It’s not the same thing as long-term aging but would still be informative. I’m already doing a lot of research with egg tempera, I’m trying to limit my time with these experiments (so I can, yes, paint!), but this would be a relatively easy one to do – I’ll let you know if I give it a try.
If you haven’t yet tried increasing the impasto potential of tempera via an emulsion (i.e. tempera grassa), I encourage it. I mix an egg oil emulsion in literally one minute: Place a tablepoon of egg yolk in a bowl, use a mini whisk to slowly blend in a bit less than a tablespoon of drying oil (I use sun thickened linseed made by a friend), and in a few seconds you have something like hollandaise sauce. Don't bother adding a resin, such as damar, as many tempera grassa recipes call for; resin is not needed (as you know, it just introduces darkness and brittleness over time).
This simple recipe creates a rich, gorgeous medium that is water-soluble, easy to combine with pigments, behaves more or less like egg tempera, but allows for a thicker blob of impasto than pure egg tempera. And since there is a history (albeit minimal) of combining these two polymerizing binders (oil and egg), time has shown them to be reliably compatible.
Please let us know if you experiment with wax and tempera – who knows, might be a great idea.
Hello Koo, and Goerge! It's always great to sit in on these conversations that the two of you have regarding ET -- I benifit so much by your collective knowledge and experience.
So here's a quick question: I too pine for a little more "oomph" and texture in the lighter passages of my egg tempera paintings, and was wondering if a small addition of Cera Colors and/or Cera Colors Medium might do the trick? I've read in other posts that mixing cera colors with other water soluable paints, such as acrylic dispersion paints etc., is possible, and thought that perhaps egg tempera would fall under the same category. In my experience, cera colors has a similar enough sheen to that of egg tempera, and when dry it's satin/matte surface can be buffed to a greater luster, in much the same way as egg tempera. I also wonder if the "waxy" nature of cera colors might not contribute some degree of flexibility and/or supleness to thicker layers of egg tempera, perhaps mitigating some of those pesky problems, like cracking? Any thoughts on this would be greatly appreciated.
- Julio R
Thanks, George. I'm thinking if I keep the "impasto" relatively minimal (1/16" or so) and no cracking results in the short term, it might be okay for the long term. Koo
Part of the reason why thick passages of egg tempera crack as they dry is the loss of volume. Water comprises a major part of the volume of the wet egg tempera and as this water evaporates rapidily the paint film does not have time to coalesce into a stable network, which introduces cracking. Slower evaporting solvents could be used to slow down the evaporation and perhaps diminish cracking, but to date the only humectants/pasticizers available or used in egg tempera have been substances such as honey, sugar syrup and glycerin. Unfortunatley, these substances make the paint film water sensitive and susceptible to damage from water.
Another reason is the brittle nature of egg tempera. Thick passages are more susceptible to mechanical stress caused by the support and egg tempera's response to changes in humidity.
That is interesting. The Italian masters were undoubtedly completely conversant in egg tempera and knew its possibilities (notwithstanding their systematic, seemingly rigid working method). Do you know if the rapid drying time of ET is the sole reason thick passages of tempera paint crack? Or might there be something about the yolk binder itself that, as it polymerizes, leads to cracking in impasto? I know I can get away with ET impasto in the short term, but it’s the long term I'm wondering about...
This is an interesting topic, because some years ago I was visiting the conservation department at the National Gallery in Washington, and there we examined a 15th century Italian egg tempera painting that had impasto pasaages in its dark green designs. The conservator and I were wondering if it contained any oil paint, because they could not analyze it for such at that time—they were only tasked with cleaning it. It was in rather good condition, too.
Perhaps the characteristic I most wish egg tempera had is a greater capacity for is dense, opaque paint in the highlights – as you know, ET just can’t do impasto the way oil can. I’ve been pushing the limits of impasto in tempera with some luck, but I want to know if I am understanding tempera’s impasto limitations correctly or not.
As you know, tempera dries, in the short term, via evaporation of its water content. Water evaporates relatively quickly, hence one reason thick dabs of ET paint aren’t possible: they would dry too rapidly and cracks/fissures would result.
I initially mix tempera paint that is, in the tempera world, relatively thick – about the consistency of heavy cream. Once properly tempered, I thin the paint considerably with water, and this thin paint is what I use for most of my brushwork. However I maintain a small pile of the initial, thicker paint for other tasks (such as sponging).
If I let this properly tempered, thicker pile of paint start to dry a bit, it reaches the consistency of something like butter (or, for that matter, oil paint). I can then apply this thicker quality tempera paint with some degree of impasto. (Granted, it is not a 1/8”+ dab as one can achieve in oil, but it is nonetheless genuinely thick for egg tempera, perhaps 1/16” or so). It doesn’t crack in the short term. Will it be at risk for cracking further down the road, as the paint polymerizes? Or is the fact that the water content has evaporated and no immediate cracking resulted enough to think I might get away with this degree of egg tempera “impasto”?
I realize I can get impasto by applying oil (or egg and oil) highlights at the end of a painting (which I generally do). However I’d like to (a) have work that is 100% egg tempera (so the possibilities of the medium are apparent, and not attributed to the wee bit of oil I’ve added at the end), and (b) better understand the nature of egg tempera and its possibilities. Wonderful and logical as the 15th century and icon working methods are, they seem at times to unnecessarily limit the medium.