[alt-photo] Re: Casein source

[Alan MacKellar]

 Christina,
I just received a liter of the Schmincke Cesein Liquid provided by Kremer
which as I think you said many messages ago, does not give me any ideas
about how much of it to mix with the pigment, and then the ammonium
dichromate.  You have given me a lot of information, and probably the answer
below, but how many ml of this Casein would you combine with say a tube of
watercolor pigment, to be later combined with the light sensitizer at the
point of brushing?

I am slow minded and had trouble following you experts on the proper
proportions.  And where did the student in your class get his/her tri-color
savings in time?  In drying of the emulsion time, use of a cool hair dryer,
exposure under UV, in development time in water?  I am a student with Ruth
this semester, and our final project is due in 2 weeks, so should I stick
with the slower gum arabic method?

Sorry to bother you at an equally busy time for you, but any method that
produces the same quality quicker is welcome.
Love to all,
Alan

----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
Christina Anderson
Sent: Thursday, April 14, 2011 11:57 AM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Re: Casein source

Dear You Two,

This is what I found interesting in Marek's website mention, why this list
is so nice to have these conversations.

I did a layer of casein on Yupo and on Kwik Print plastic. On both I was
able to wipe off pigment like wiping chalk off a chalkboard. However, if
what the website says is correct, that if you can wipe paint off you need
more binder, then I will go back and revisit Yupo and Kwik Print paper with
less pigment/more binder. So until proven guilty, these papers are not out
yet.

Two, the benefit of ammonium caseinate powder is there is no additional
chemical needed, no heat, just mix n go. It whips up to egg foam, subsides
in a couple hours to a pancake syrup consistency (thinner than the Schmincke
which is a very thick corn syrup) and gets more watery in the week. Very
thin, fine, works fine even two weeks later except that if using earth
pigments it must be shaken (as in gum, too). I use thymol as a preservative.
The watery solution doesn't go "off" and become unusable, albeit thinner.

Three, the fact that in the ammonia recipe the chemical reaction is created
over time with no heat is probably why the ammonium caseinate works so well
for me and not the sodium caseinate, that it has the "reactor" in it already
which the sodium does not. My sodium caseinate is still a rubbery glob after
several days, only usable if heated to a liquid, just as gelatin.

The odd thing about casein is 40g mixed in 400ml water, my proportion, still
only produced 400ml, of final solution. In other words the powder at 10%
doesn't add enough volume to make it worth mixing first in 300 and then
adding water to 400ml.  Granted, evaporation happens in MT with 20%
humidity...but when Marek's site says 2 parts casein + 16 parts water I
think it really does end up to be very close to 2 IN 16 not 2 IN total
volume 18, not that there is much difference, the former being 12.5% and the
latter about 11%.

Since Schmincke and Kremer provide a liquid version of casein binder do you
think there is a market for the ammonium caseinate powder? Wonder why the
paint companies don't provide the ammonium caseinate? There's got to be a
reason, perhaps a viscosity reason, that just regular casein is sold only it
seems.
Chris


Three, the two recipes on Marek's website say this:

	. 2  parts Casein Powder
	. 16 parts water
	. 1 part Ammonium Carbonate
	(or clear liquid ammonia*)
	. Dry Pigments paste water

OR

	. 5 parts Casein Powder
	. 9 parts Cold Water
	. 2 parts Borax
	. 9 parts Hot water


Christina Z. Anderson
christinaZanderson.com