Re: Casein -> it's the paint
Thanks Alberto,
I thought about bleach too, thanks for mentioning it anyway; I may switch
to bleach later, since even being very diluted, ammonia smell is much more
unpleasant compared diluted bleach. I currently put 3ml of 25% ('910'
proof) ammonia per litre of development water (exactly one tenth of the
amount I use for dissolving casein) and that seems to be a little on the
strong side. Will further decrease ammonia amount in development water (to
something around 1ml per 1 litre).
I mix mine as following: add 10ml room temperature water to 0.8g casein,
wait 5-10 minutes then add 8 drops of 25% ammonia. (Makes something like
0.33ml pure ammonia which is equivalent to 3.3ml 10%, you were using 10x
the ammonia I'm using right now!) Dissolution is virtualy instant (5-10
swirls in about 3-4 seconds), but I stir a little more to be sure.
Nice images/concept BTW!
Will drop Yupo aside and continue with good old watercolor paper in order
to get a good grab onto the process first...
Thanks again & regards,
Loris.
25 Mayıs 2009, Pazartesi, 10:26 am tarihinde, Alberto Novo yazmış:
> Loris,
> I was out of home for fiyur days so I reply you only when you are near to
> th
> solution of your problems.
> I printed in casein dichromate about two years ago (I have some prints in
> the Rodolfo Namias Group website, search for "Motherhood"), with the aim
> of
> acheving some single layer casein prints.
> The dried casein+dichromate is hard to dissolve in plain water. You can
> use
> (like you did) some ammonia in the development water after the print
> washed
> off most of the dichromate in the first 10 minutes, or also some drops of
> hypochlorite. If the paper still won't spoil, try also with a garden
> sprayer
> from a distance on the vertical print out of the tray.
> Casein print has a longer tonal scale than gum, and you can get stained
> highlights if you don't use sized paper. You will be able to put in the
> casein solution about ten times the amout normally used with gum.
> As for the preparation of the alkaline casein solution, I have found
> useful
> (and harmless both for me and the casein) pouring 0.8 g of casein and 10
> cc
> of 10% ammonia in a small (125 cc) glass jar with an hermetic lid (the
> type
> used for pickes and for sterilizing jams and peeled tomatoes). Then I
> heated
> the sealed jar in hot (60°C) water for about 15', swirling the solution
> from
> time to time. After this, I put it in the refrigerator.
> The solution stinks, so it is better to have it cooled before opening the
> lid.
>
> Alberto
>
>> Hi all,
>>
>> I tried with powdered pigment and this time (3rd trial) got an image.
>> So,
>> (for the moment) I conclude that the reason of not getting an image in
>> the
>> first try was the acrylic paint. The 2nd was made w/ the same emulsion
>> but
>> this time by putting a little of ammonia in the development water (by
>> suggestion of a list member), it was better compared to the first time
>> (reacted to force development) but nothing near to usable / successful.
>>
>> I'm making these tests on plain Yupo paper. And casein is much much
>> better
>> in adhering to the paper -> in all my trials with gum on plain Yupo, the
>> emulsion had left the paper completely...
>>
>> A side note: I got tonal reversal with the 3rd trial -> it was a very
>> dark
>> / contrasty mix exposed only 1 minute under UVBL (2 parts casein/pigment
>> +
>> 1 part 5% AD).
>>
>> Regards,
>> Loris.
>>
>>
>> 22 Mayıs 2009, Cuma, 10:06 pm tarihinde, Loris Medici yazmış:
>>> 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,
>>> Loris.
>
>