From: Judy Seigel (jseigel@panix.com)
Date: 11/06/00-06:55:48 PM Z
On Mon, 6 Nov 2000, Katharine Thayer wrote:
> ....The person who makes absolute statements about gum
> printing, for example, comes a cropper every time. I've heard a gum
> printing "expert" say for instance that ammonium dichromate is no good
> for gum printing because it always causes dichromate staining. This is a
> ridiculous statement that can easily be proved false. What the person
> really means, and should say, is "Potassium dichromate works better with
> the kind of light source, the paper, the whatever....that I choose to
> use, than ammonium dichromate. You may find ammonium dichromate works
> perfectly well for you if you choose a different light source etc etc"
When I get my correlative variables together I'm going to address the
terminal fallacies in that whole business about models for testing --
methinks the fellas are having fun with statistics, and word games, but
have never followed a REAL process in such a manner. For one thing the
*theory* assumes that the variables progress constantly. They don't. As
other variables change they do too, but not on a mathematical model,
rather quixotically.
Here's an example-- in silver technology it was found that such & such
occurs ONLY if the gelatin temperature is raised to x degress for x length
of time. Was that found by theory -- or serendipity? you could test til
the cow jumps over the moon and not stumble on that unless you have a
hunch in advance.
All the hand coated process (if not ALL processes) have kinks & vagaries
NOT given by a mechanistic (which that is) theory system. I once realized
by reasoning backwards from experience that what had been in the tray
before I toned a silver print changed the effect dramatically. Happened
twice & it dawned on me in retrospect. Where is that kind of "finding" in
the "theory"? If it's there, probably drowned in the wretched excess.
Has anybody said yet that *theoretically* the bumblebee can't fly? (Of
course I don't know that for a fact, read it. Maybe they patched up the
theory after they noticed the anomaly.)
Wayde says "the whole idea is to get more information from the same amount
of work." I'd say you probably don't get more "information," or useful
information. More likely busywork to fill in on a chart. Of course what
you will DEFINITELY get more of is work.
However, the point about the potassium vs. ammonium dichromate is an
interesting one. I hazard here an absolute statement -- my own tests
showed that if the solution strength is the same, the staining is the
same. That is, bring the am di down to 10% (or whatever your k di) and
voila. I wouldn't buy a used formula from person who made that statement,
or should say "persons," I've read it several places.
However, what I never figured out is where all that staining comes from
anyway... I rarely see any. But I use only am di.
Judy
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