> I was studying some German Pictorialist gums that Stephen White had in
his > gallery about 15 years ago, they were large, maybe 16 x 20 with
multicoats > and perfect registration. They had some indications that
there had been > some kind of varnish on the back side. When he wasn't
looking, I wet my > finger to see if it was library paste and I concluded
it wasn't. It seemed > to be solvent based. I guessed then that the artist
had used something like > an alcohol based shellac to glue the paper down
to a substrate and then used > alcohol to remove it. In this case it the
shellac was not washed off > completely, as just enough was used to remove
the print and to get most but > not all of it off. Our ancestors were not
as dumb as we look. >
Dick,
I've come across old books & articles saying you can fasten the paper to
either a zinc or aluminum plate by shellac. As I related in these pages
last year, my attempt to do so was a disaster: To make the paper stick
required *very* heavy shellac, actually 2 coats, and when it came time to
remove, it took all day & ripped the paper. Since then, I think it was
Mike Ware, suggested that acetone would have done the job better, but I
haven't had the heart to try again. (Meanwhile, am trying Luis's idea of
gelatine as the glue, to be removed in hot water, with so far mixed
results, more to follow when, as & if.)
Also since then, I came across *another* article which detailed the
laborious process of grit-smoothing, then *waxing* and polishing the zinc
plate so it would release the paper when the time came (omitted in
earlier mentions), which sounded about as painful as preparing a plate for
daguerreotype, and failed on that account to appeal.
And while on the topic, I reply to FotoDave's suggestion of simply taping
the wet paper to the substrate. This didn't work for me as, unless the
paper was glued down, it buckled when wet (wetting it first helped some,
but not entirely). The buckles, which can occur immediately, prevent
smooth coating -- when the paper is freestanding you can unpin one side &
stretch to get the buckle out. Also, they never entirely disappear when
dry, giving problems with both re-coating & reregistering. Perhaps with a
*really* heavy paper (say 600gsm) this doesn't happen, but then you
probably don't need a substrate anyway.
However, if one does want to fasten paper with gum tape (and I recommend 16
gauge aluminum over plexi or glass, which have to be thicker, in my
experience, leading to problems in vacuum frame), you can waterproof it
with shellac or liquitex varnish. The art supply store sells gum paper
tape at $2 a roll. But I find duct tape better for the purpose. It's
already waterproof, no coating necessary, and also pretty cheap. It leaves a
gummy residue, but gets cut off anyway.
Judy