i haven't printed printed with casein, but when reading your mail, i remembered an article on egg-tempera print on unblinkingeye - the only other alt. process that i've heard of that uses acrylics. (found here: http://unblinkingeye.com/Articles/TPrnt/tprnt.html )
did you try to develop the print by force (running water, brush etc)? the method of developing egg-tempera prints in the manual is to "Develop/wash in a flat-bottomed tray containing water, with a dash of dish washing up liquid added. Use a plastic foam roller to develop the image". maybe acrylics generally need a little bit of force during development.
Von: "Loris Medici" <email@example.com>
Gesendet: 22.05.09 21:08:37
I did my first casein trial yesterday evening, w/o any success. See below:
- 0.8g casein (Kremer's)
- 5ml tap water
- waited 10 minutes (to let casein absorb water - I'm not sure if that's
necessary but did so anyway, I was not in a hurry...)
- added 8 drops of 25% (910) ammonia (it seems to be a lot, will try
halving the amnt. next time)
- I mixed the slurry (cream consistency) until it looks homogeneous
- I added 5ml of 5% ammonium dichromate (it turned to yellow - because of
excess alkalinity I presume...)
- I mixed the solution (not a slurry anymore, pretty homogeneous looking
solution slightly less viscous than my usual gum coating mix)
made up a coating solution by adding the dichromated casein solution to
a very small amnt. of W&N acrylic color (burnt umber)
- coated the paper, dried with a hair dryer, humidified the paper with an
ultrasonic humidifier, exposed for 2 mins. under a bank of UVBL tubes (I
didn't get a dichromate image after exposure)
- developed(!) face down for 20minutes
I got absolutely no development, no pigment coming off, no dissolution of
binder at all.
What could be the cause?
Overexposure? Using acrylics? (But I know someone - Guido Ceuppens - who
uses acrylic colors with casein...) Both? Any other thoughts?
Will try with only 30secs exposure tonight...
Regards & thanks in advance,