From: Judy Seigel (jseigel@panix.com)
Date: 11/06/00-09:52:06 AM Z
On Sun, 5 Nov 2000, 1232-553-1 wrote:
> >>> ...but gelatin is death to Buxton.
> What does you mean with this?
I'd have to go back into the file (tests done 4 or more years ago) for
specifics, but in general --the emulsion printed paler and flatter than
without the size. Of course you could probably still build up density with
many coats, but that defeats the purpose of Buxton for gum, which is
maximum hit in one coat. For multi-coat gum in any event I'd pick a
sturdier more stable paper with a tougher surface.
> >>> Which is to say, Buxton requires/can tolerate no added size.
> I did additional gelatin sizing (and hardening with formalin) for
> my carbon work - the result was the own paper which I liked
> esthetically and made me able to produce great carbon transfers.
> What was the problem or why didn't it work for you?
I think we tend to think that just because gum printing and carbon use
many of the same materials, they work the same, but I get the impression
they're completely different !!! I remember when we did some exposure
tests years ago, Sandy King & company found a whole other profile for bulb
range for carbon than I found for gum, a BETTER scale, with, as I recall a
daylight fluorescent. For gum the exposure time with daylight fluorescent
tripled and the scale about vanished.
In carbon transfer, I take it that you mean the exposure was done on a
different surface, then transfered to the Buxton for development.... which
is, I gather, purely mechanical. I would assume elements don't get into
each other the same way... Although of course it's possible that a
different worker, using different ingredients and a different gelatin
might well have results very different from mine. (In fact as we know,
just opening the door can cause something completely different.)
Of course I definitely do not claim to have tested the matter
exhaustively, just found what for my purposes was sufficient: no advantage
for me from added size to Buxton, and on to the next tangle. But speaking
of Buxton, do I remember rightly that it was also supposed to be good for
inkjet???
> >>> Buxton itself, unlike most commercial papers, has no gelatin size,
> either
> >>> internal or surface. There was some reason I forget now why that's
> better
> >>> for platinum,
> Due to it's PH value, as it doesn't cause chemical reactions with the pd/pt
> process I think>
Ahhh, pH. In gum I think that stands for Perplex the Humans. Or maybe I
need better pH instrumentation. In any event, there was the day I tried to
figure out why four different gum arabics all nominally 14 Baume printed
so differently and with such different *speeds*, one being more than twice
as fast as another. There was no correlation with pH (as well as I could
measure with a wretch of a $40 digital stick), and all measured about 14
on the (hydrometer or hygrometer-- you know what I mean)...
cheers,
Judy
> >>> Also, tho Mike says to the contrary, the Buxton has no wet strength -- I
> >>> suppose it's OK for small platinum prints that you only wet once,
> It's indeed very fragile and should be handled with care - with carbon I did
> additional sizing and it was o.k. in wet processing.
>
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