From: Christina Z. Anderson (zphoto@montana.net)
Date: 02/07/03-11:38:48 AM Z
I never knew this, too, and I had put a chapter in my workbook on paper
negs and also recommended them for alt processes, and last semester either I
read, or someone told me, or it was on this list or the pure silver list
that "RC papers have a UV blocker so they don't work well for alt process UV
sensitive processes like platino, cyano, and VDB" is the way I wrote the
statement in the margin of my workbook (for the next revision). So I am
tracking it down for you. However, apparently you do not find this to be
the case, which is GOOD news for me because then I can continue to say what
I've said! But maybe it is partially true of RC papers and it requires
peeling, yet not true of fiber....I'm waiting for a call from Kodak and
their opinion.
Speaking of which, as I am researching about 10 alt processes to get
all my notes in one place and one format--Pagemaker--I have a stack of 15-20
books at my kitchen table. With each process I read all the books, and take
notes. I am absolutely amazed at the inconsistencies and wrong information
published. I know we have talked about this before on this list, in
specific, related to Scopick's pigment test (let's not rehash that again),
but really! For instance, one formula for argyrotype had the elements mixed
in 1 ltr of water, when all other books had the same amounts of ingredients
mixed in 100ml water. I think that is a pretty big mistake (?) unless there
is the ability for argyrotype to work under all kinds of dilutions.
More importantly, to answer the original poster's query about paper
negs by reversal, here is the following I found in Worobiec's Beyond
Monochrome:
1. Put neg upside down in carrier.
2. Expose it 3 stops darker than it should normally print.
3. Develop as normal; you'll get a black print.
4. Wash.
5. Put the print in a tray of sodium sulfide at normal strength for sepia
toning (1:7-1:9) for 2 minutes. It'll be yukky green/brown.
6. Wash
6. Put in tray of 10% pot ferri bleach for 3-4 min. A reversed image will
now appear as the bleach removes the original overexposed image leaving a
sepia brown negative. White lights can be turned on about halfway thru this
process.
7. Wash, fix, wash, and dry.
8. Use to print, emulsion to emulsion.
Contrast controls are in initial exposure length or filter used.
I have not tried this, but if someone would, report back.
Chris
> Christina Z. Anderson wrote:
> > Martin,
> > Some have said that UV inhibitors exist in paper, and thus paper
negs
> > are unsuitable for alt UV processes.
> This is news to me, Chris, and I don't recall reading that anywhere.
> Could you give me a source? I've used all kinds of paper negatives,
> oiled, waxed, and not, for gum prints. How the exposure time varies
> relative to film varies according to what film and what paper, but in my
> experience paper doesn't in general give a substantially increased
> exposure time over film, and what increase there is would be
> attributable to the thickness of the paper and the fibers in it, I would
> think. If that is all they're talking about, why don't they just say
> that, instead of invoking a term like "UV inhibitor."
>
> The one thing that doesn't work is unpeeled RC paper; that DOES have a
> UV inhibitor in the form of a big slab of plastic. I even used
> double-weight fiber paper once for a negative (took a ton of oil for the
> 16x20 paper and still wasn't really soaked through) but the exposure was
> only 5 minutes as opposed to my usual exposures around 3 minutes.
> Katharine Thayer
>
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