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  #31  
Old 26-07-08, 01:31 AM
dbclemons dbclemons is offline
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Thanks for that info, Jennifer. It's interesting.

Kama's comment about a shelf life of just 3-5 weeks in refrigeration is just not correct, in my experience. I've used it for up to 6 months or so and seen only a slight degradation as it becomes weaker but with no sign of bacteria or spoilage using just borax and their own casein powder. The paint I make still adheres just fine after all that time, if I don't use it up first.

The only bothersome odor I've had with casein is when made with ammonia. In that case I'd recommend ventilation, but only when you're first making it. Shiva paints have a very noticeable odor, which may be ammonia or a preservative/both. It will dissipate after a few hours. Borax is odorless, as is tri-sodium phosphate. There is a slight musky odor with borax casein, but you have to stick your nose in it to smell it.

I really welcome that Kreidezeit link. I wasn't aware they re-distributed someone elses casein paints. Good to know. Reading through that link it looks like it contains a lime base and possibly clay or filler if it's "a bit on the pastel side."

The Casein Primer that they sell must be the same one made by Kreidezeit/Mike Wye which uses borax, according to its technical sheet. I have read that ammonia makes a stronger adhesive with casein than borax, and lime even moreso, but I'm happier using borax.

I've tried out glycerin as a retarder for casein and it does keep the medium wet longer, but I've not really found it useful in my application. I have no experience with it's compatiblility with ET. Only a small amount is ever recommended as too much makes casein gummy. Humectants like diluted honey or corn syrup can also be used. Acrylic retarders as essentially the same thing (emollients like Propylene Glycol.) Recommended amounts I've seen are diluted glycerin 5 times in water, and add @1 teaspoon of that to @1 ounce of medium.

Last edited by dbclemons; 26-07-08 at 01:34 AM.
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  #32  
Old 26-07-08, 08:27 PM
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jpohl jpohl is offline
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The Kreidezeit seem especially useful for interior mural painters.

I just got an email from kama saying they were sorry for making a mistake when i asked about a particular pigment... saying they only did custom colours in oil, and had made difficult to find colours in the past for several clients. (still useful to know.) They did have the pbr24 naples yellow (or non toxic, highly lightfast alternative recommended on handprint, which i had only been able to find on the williamsburg site at 18 dollars for 2 oz. It's hard to tell though, as many of the suppliers in europe don't seem to list the index numbers.)

Would love to hear if anyone knows about the glycerin under egg tempera. I wonder if shiva or zecchi put anything like that in their emulsions. (One of the reasons I've avoided acrylic is because the ammonia which can make it more dangerous than working with oil if you tend to get it on your skin. Perhaps working with the premixed in small quantities may suit me better for that reason.)

Last edited by jpohl; 26-07-08 at 08:32 PM.
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  #33  
Old 22-09-08, 10:02 PM
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Dimitris C. Milionis Dimitris C. Milionis is offline
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this has been quite a good thread
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  #34  
Old 13-11-08, 11:19 PM
Bruce Cook Bruce Cook is offline
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Margaret Krug (senior lecturer at the Whitney Museum, instructor at Parsons) has a nice section on casein (making your own emulsion and paints) in her great book, "An Artist's Handbook: Materials and Techniques"... check it out.
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  #35  
Old 19-11-08, 08:23 PM
otto otto is offline
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Angry How strong a casein solution?

I've made homemade casein paints according to several techniques books, including the Sinopia catalogue recipe. Most suggest after making the casein-borax solution (totalling 18 ounces), to dilute this with an additional 6 cups of water before mixing in the pigments. I've let this paint dry, but it always powders off pretty easily (as does dried Shiva Caseins). Too weak a binder, I guess, but I also don't want the binder too strong, since this might cause cracking. Does anyone here add the additional 6 cups water, since this sounds excessive?
Also, does anyone know if the Shiva Caseins are emulsion paints (with oil,etc) or straight casein?
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  #36  
Old 20-11-08, 01:56 PM
dbclemons dbclemons is offline
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6 cups for 18 oz is way too thin. I wouldn't dilute watercolor that much. I couldn't find anything at Sinopia about adding that much water. Start with the original volume and adjust it just enough to accomodate the pigment paste into a workable paint. It won't crack unless you apply it too thickly.
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  #37  
Old 21-11-08, 02:27 AM
otto otto is offline
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Yeah, It seemed like way too much water to me. The recipe is actually in a Kremer Pigments catologue 2005. It also appears the same way (adding six additional cups of water) in An Artist's Handbook by Margaret Krug (2007), otherwise a good techniques book. Reader beware!
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