From: Joe Smigiel (jsmigiel@kvcc.edu)
Date: 02/13/03-09:31:14 AM Z
>>> cactuscowboy@attbi.com 02/12/03 23:34 PM >>>
----- Original Message -----
From: "Judy Seigel" <jseigel@panix.com>
(snip)
other people said they
> too had found it immaterial. I THINK one of them was Joe Smiegel, tho
> don't remember for sure, and if it wasn't, Joe I apologize for taking your
> name in vain...Tho of course it's, um, flattering that I'm the only one
> Katharine Thayer remembers...
******
I find it easy to believe that some individuals with limited experience in
gum printing might actually buy your arguments. I don't. As for Mike Ware,
the fellow you've put on a pedestal, he's not written anything about gum
that I don't already know from experience. Nor have you.
(snip)
******
Dave Rose
Cactus Cowboy
******
Dave,
I would consider myself to have plenty of experience gum printing and not, as you imply, "limited experience." I certainly have done the pigment tests several times, by the book(s), and take issue with the results based on my personal experience, not from "buying" anyone else's opinion. In fact, I find much of what has been written in the literature and on this list about gum printing to be at odds with my experience.
I've even posted jpegs online of the results of pigment staining tests I've run which clearly reveal for example, that Pthalo Blue stains certain papers terribly. A quick review of recent posts to the list reveals some learned practitioners supporting this idea, and some finding the opposite results. It is important for an individual to run the tests personally rather than relying on what one may have read, here or elsewhere. I might add that my academic experience has instilled in me the virtues of proper experimental design and implimentation. I'm confident that variables relevant to my environment and practice were controlled adequately when performing my tests to the extent practically possible. (And practicality is a big issue, IMO.) Likewise, others on this list with similar training have done the tests and found what works for them, although their results may differ from mine.
Having said that, my two cents on the pigment staining test is that the addition of dichromate sensitizer affects the viscosity and setting time of the gum emulsion. Without the sensitizer addition, the pigmented gum sets quicker and does not allow the emulsion to penetrate into the paper compared to a thinner sensitized mix. Andersen's test without sensitizer allows one only to gauge the relative staining of one quantity of pigment against a different quantity. As soon as you add sensitizer, whether in actual printing or in stain testing, you are suddenly dealing with an entirely different set of conditions. To test for a practical and absolute staining potential, sensitizer must be added to the mix. The former is general and IMO of almost no utility, while the latter is specific and practical.
Your mileage may vary.
Joe Smigiel
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