From: Judy Seigel (jseigel@panix.com)
Date: 12/07/02-02:45:31 AM Z
On Fri, 6 Dec 2002, Liam Lawless wrote:
> I beleve that the majority of art papers are now buffered, although they're
> not always described as such. Indeed, "permanent" papers should contain
> alkaline reserves according to the ANSI Z39 (US) Permanent Paper Standard.
> Anything labelled acid free and not specifically designated unbuffered is
> probably buffered. When did buffering start? Don't know, but according to
> Silvie Turner (The Book of Fine Paper): "A move to make certain grades of
> machinemade papers (mostly artists' and book papers) acid free is due partly
> to pressure put on manufacturers by librarians, particularly in the USA."
>
> pH pens? Don't know - never had one, never seen one. But probably yes -
> try damping the paper (pure water!) first if it doesn't work dry, or soak a
> piece and test the drippings.
They're really like pH markers, that is have a felt nib and draw a line
like a small marker so you can test paper just by making a mark on it.
Pretty nifty, quick & simple. we had a pH fest with it in class, marking
all the student's papers (in a corner) and finding a wide variety of
effects. Some papers are neutral, some not.
A couple of years ago a book artist customer at Ny Central found
an Arches paper was acid -- which Arches denied... guess i'll look for
that pen & see if there's any juice left in it..
> That the image "pops" in hypo is I think explained by the fact that it makes
> the iron soluble. KOL describes one of Herschel's discoveries: "that on
> exposure to light ferric salts become reduced to the ferrous state, and that
> the ferrous salts so produced can combine with or in turn reduce other salts
> to create an image."
What struck me was that it's instantaneous...
But in one of these messages, which I seem to have lost, you said fairly
strong fixer doesn't bother VDB -- or did I read it wrong? anyway, my
tests with 3 strengths of plain sodium thio in water showed that anything
stronger than the weakest (from memory 1 tbsp in 16 oz water) did indeed
bleach out the print after about 30 seconds.
J.
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