From: Judy Seigel (jseigel@panix.com)
Date: 08/02/03-12:58:15 AM Z
On Thu, 31 Jul 2003, Christina Z. Anderson wrote:
> > However, my point isn't that Anderson INVENTED pigment stain,
>
> Hmmmm, that was your point of a post a while back that I was going on, as I
> quoted from your post. So now, you are saying, that there is no
That Anderson "invented pigment stain" was of course hyperbole, but refers
to 2 things: he made it a signature issue and he made it much worse with
his methods... But you apparently haven't understood what's wrong with the
GPR test -- or for that matter what's wrong with the simpler tests of
1905.
None of them do actually predict staining, because none of them involve
exposure & the chemistry of the exposure changes everything. Equally
important, Anderson's test is NOT the same as what's in, for instance, the
Practical Photographer book, even aside from his over-elaboration.
Harold Holcroft has a sort of test (Practical Photographer, page 36),
which would actually be better than Anderson's because it at least
includes the bichromate. But neither of them include the exposure, which
in case I forgot to mention it, CHANGES EVERYTHING. Maybe it will help if
I say that although I have OBSERVED this, the explanation comes from a
higher authority -- in fact possibly even on this list, ie., Mike Ware.
The actual chemical reaction for staining needs the exposure and the
dichromate.
There's so much detail on this (viscosity, reduction, impurities, surface
of the paper, etc.) in other list go-rounds, I won't repeat (& it's
clearly an exercise in futility anyway)... but I promise, just rubbing the
gum & pigment on the paper to see if it washes off -- as you mention and
one of the other 1905 authors suggested, may have some relevance (or not),
but is AT BEST just a hint. I repeat, the exposure and the dichromate are
crucial ingredients.
On top of which Anderson overelaborated the point to absurdity --
measuring the LEAST amount of pigment that he didn't detect staining for,
ie, quantifying irrelevance. Then, and this was the point of my point:
those weak coats got into the canon and profoundly affected gum printing.
(Not to mention that, as I have shown, double the pigment can mean LESS
staining in an actual print -- see P-F #2, page 46. Ware's explanation for
that is the increased viscosity.)
I note in passing that Holcroft's claims for his test were much more
modest, simply a check on "solubility and clearing." As a guess, I'd say
about half the gum articles and books of the period mention "staining" as
one of many variables, most give different explanations, none dwell on it
and about half don't mention it or hardly. Interestingly, many say you can
solve the problem by adding gum -- but Demachy, at least in the PP book,
says the problem IS the gum.
He wrote: "I have never experienced the difficulty in getting pure
highlights *at will* that many gum experts complain of..." (Emphasis in
original.) He attributes staining to stale gum solution, ie., too acid.
C H Hewitt on the other hand, in the very next article, says the opposite.
He advises using gum 2 or 3 weeks old and "very slightly acid." He sees
"dirty highlights" as a factor of the paper, and says the remedy is to
size the paper.
And so forth... In other words, there is no consensus (which is
understandable since the premises were all over the map and probably
wrong).
> long-winded-complicated-pigment-stain test in any of the books before
> Anderson. If that is your point, I fully agree with you--no book has fully
> outlined a step by step method of testing pigment stain in a number of
> paragraphs, as has Anderson. OH, except Demachy in 1898 (does he count?
> :)).
Which article/book is that?
> But to return to the original point I was making (and, recheck your sources
> I mentioned, the paper test is in there--I really try hard not to lie on the
I have rechecked my sources, tho it's clearly a waste of time, and I don't
accuse you of lying, rather of blurring, or misunderstanding the issues.
> internet-wink, wink, hehehehehe) --the problem of pigment stain was there in
> the very beginning of gum, and most sources say to coat an extra piece of
> the paper, or turn up an edge with no exposure, or to do an accordion of the
> paper, to see if the pigment leaves the paper with development.
>
"MOST SOURCES"??? That is definitely not my finding... (as noted above),
tho the point is still a detour. My point, bringing all this on, was that
Anderson's OVERELABORATION of a mistaken "test" changed gum printing from
a vigorous often one-coat print to a pale and fuzzy look caused by the
many coats-- leading to the "can't do fine detail" mantra that is in so
many (tho not all) modern sources, including Keepers of Light, about which
more before whenever. (And I do not now recall the can't do fine detail
thing in ANY of the early sources.)
> I've printed with 100% sodium dichromate, too, and reported to this list
> that surprisingly, 100% sodium dichromate was NOT fast. Ugly, but not fast.
But presumably Anderson thought it was faster, in fact he may have said so
somewhere. But wait a minute -- Are you saying that 100% sodium
dichromate isn't faster than 30% ammonium dichromate? As I recall it was,
and if sanity fails to return sometime soon, I'll check the file.
> Kosar says sodium and potassium are equivalent in all respects, presuming,
> of course, they are at the same level of concentration.
Clearly he got that from me...
cheers,
Judy
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