>>
...I just like to share the preliminairy results on Bovine Albumen, I
picked up the principles through Mike Robinsons web page and the archives
of the Alt. Photo list , and feedback from the Alt. Mailing list. I hope
to get maybe some tips and tricks for further experimentation.
I started out with the idea of using purified BSA (Bovine Serum Albumen,
98-99% pure), instead of eggs. So I calculated that your recipe asks
roughly for 0.8 g Albumen per ml. I managed to get about 0.31 g BSA per ml
(Very sticky stuff, and I foolishly poured the distilled water on the
powder instead off the other way around, so that kept me quite busy..;-).)
, and added the NH4CL and Acetic acid. The resulting solution was quite
thick, high viscosity, syrup like. Some trouble to remove the air bubbles,
they literally get stuck in it. I floated the paper (Simili Japon) on top,
after already 1 minute it starts to curl up, had to press the edge down. I
decide to test both single and double coating. The papers dried quit
quickly, curled heavely, trying to un-roll them made (audible) cracks.
Took a few, and imeressed them totally in the 70% Isopropanol/NH4Cl, and
tried to float them a second time, this didn't work, it caused "tears" and
streaks of albumen on top of the first coat (probably the first coat is
enough?)
Sensitizing
Tried first to use your glass float trick, was not succesfull, maybe to
little volume, and also the single coated paper was not well coated
(airbubbles). Used it nevertheless. Got an surprisingly good image after
just 2,5 min. UV bank exposure! Deep dark brown shadows/edges, and almost
the complete Stouffer wedge (upto 20!), washing (milky) and fixing
ofcourse lightend up considerably, bits of the emulsion were getting loose
from the paper, so I stopped the washing, and dried. The endresult looked
quite pleasing, brown, with a airdried fibre-base gloss. I do need a
higher density neg. though.
The double coated papers I sensitezed with a brush (taped them on a glass
plate), seemed to work nice, but once exposed and processed, they look
awfull and very pale. No image on the streak/tears from the 2nd coat.
Probably a combination of the bad coating, and to little AgNO3..
I did not yet employed goldtoning, but I ordered Tetenal Gold Toner (was
taken back by the price of pure goldchloride)
..so this has become quite an extensive post. Thanks for your time, and I
hope I get some feedback!
Groet,
I quot again the answer that Dan posted :
>>Your albumen solution definitely sounds too thick - easily the cause of
cracking and drying problems, as well as loose emulsion in processing.
My albumen solution is the consistency of, well, eggs, really. Stop
measuring and go for the right feel - usually you want the best gloss,
without being too thick (it'll crack later), although I can of course
only speak for myself. If you've got a good gloss on the first pass, why
bother with the second? We chicken-printers need to do it twice to get
it right...
Dan Estabrook
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