You are right, what I meant with "original" is only the format and that I
never enlarge my negatives in order to keep its whole quality (when using
this large format). For carbon printing I make every time a doublicate
negative to avoid contact with dicromates and to avoid damages of the
original negative. Contrary to your method I use a one-step-reversal-process
(with a bleacher like E6 for color slides) to produce the printing negative,
so I get a good one for direkt transfer process without any loss of sharpness
(which could happened when printing upside down). When using the double
transfer process I develope the printing negative as usual but this does not
work with baryta paper as a final because of its hardened surface.
> I'm not sure what you mean with /qm
qm = square meter
> Also, 12 hours is likely to be much too long for best results. As soon as
> dry, the better. Try two to three hours. I notice below that you develop
> 20-35 minutes and you do mention fog problems, so this is probably because
> drying goes on for too long.
I read your book and so I was realy surprised that it worked. Presensitized
tissue 12 hours dried has the same amount of fog (which does mean nearly no
fog!) than "normal" tissue sensitized later with a brush in a 3%-solution
and dried in 90 minutes!
The exessive developing time and the need of heavy agitation is regardless
wether I use presensitized material or "normal" tissue with need for
sensitizing step. The image starts to apear in correct density much earlier
but I need agitation and prolonged developing to wash of the gelatin/pigment
slime.
In every case I use fresh material and get best results with clear highlights,
deep blacks and fantastic graduation in middtones and maximum densities
as typical for carbon. My way seems to be more troublesome than yours,
but I do not know why because its the same with "normal" tissue as I
explained.
How do you achive short drying times? I fear that higher drying temperature
could cause fog or do you add a drying agent when coating presensitized
emulsions?
> How much water does this amount to per print? I always found that two hot
> water trays were sufficient. One large, deep tray in which I'd develop a
> lot of prints and perhaps a smaller one but this was often not required.
Your method sounds much more economical! I use so much water to give
pigment slim no chance to adhere on the final and to replace water which
cooles down in my trays(I have no heater for my trays with could keep
temperature constant). It was only a suggestion and I stop changing water
when there is no visible slime. I will try your method.
Do you think that it is necessary to add glycerin and/or sugar to a
presensitized emulsion whith will be processed soon after drying or could
the dry gelatin crack without it?
Another question of interest could be the permanence of gelatin. Good
pigments (like boneblack) are nearly absolute permanent.
But gelatin could turn to grey or yellow and this would change the prints
color or (in theory) higher the contrast. Do you know anything about the
permanence of gelatin and how long such a process will need under certain
conditions?
Stefan Stecher
stefan.stecher@htw-kempten.de