>
> Since I have recently acquired a printing press I've been reading lots
> about printing. I came across a reference in John Muench's book A
> PAINTERS GUIDE TO LITHOGRAPHY published by North Light Publishers
> (1983) that suggests that lithographers gum is probably not gum
> arabic......
> Muench writes:
>
> Gum arabic has always been a key ingredient in the various formulae
> used in processing and printing lithographs, both stone and plate.
> Originally the substance came in amber lumps from the gum acacia tree
> of Africa and was dissolved in water to make a syrupy liquid for use
> in lithography. In recent years, however, gum arabic has become
> nearly unobtainable, and various substitutes have been found, some
> synthetic or cellulose and others stemming from such unlikely sources
> as cactus. This being the case, the term "gum arabic" is seldom used
> today. It has become in the lexicon of the lithographer, simply
> "gum."
>
Greg, that's first I heard.
But let me add that I have a jug of gum arabic bought about the year that
book was written labelled "Liquid Gum Arabic, 14 degrees baume, A high
quality Non-Souring Solution of PURE GUM ARABIC."
And another bought last year from RBP Chemical company labelled "Gum
Arabic 14 degrees Baume, 100% Gum Arabic Solution."
And a third bought somewhere inbetween that I can't lay hands on this
minute also with "Gum Arabic" label.
Plus during this time I've bought at least 3 kinds of powdered gum, also
labelled Gum Arabic, from Light Impressions, among other sources.
Is this book you're quoting English? The English have invented all kinds
of problems with gum arabic to promote a local product made out of boiled
beef bones called "Gloy." I will add (in case anyone is listening for a
change, by mistake) that I have tested Gloy *extensively* and in
*****NO****** case found it superior to gum arabic, in only a few cases
equal. If you import it, Richard ...... lots of luck. (Terry is wrong.)
Judy