From: Judy Seigel (jseigel@panix.com)
Date: 11/08/00-04:31:29 PM Z
On Wed, 8 Nov 2000, J. Wayde Allen wrote:
> On Tue, 7 Nov 2000, Judy Seigel wrote:
>
> I'm assuming that your exposed and developed test strip is paper that has
> been sized, hardened with Glyoxal, coated with the gum emulsion, exposed
> for some length of time, and then water developed? Are you exposing
> through a step tablet?
Yes.
> What do you mean by blank? I'm guessing this is a
> piece of the same paper that is sized and hardened with Glyoxal - correct?
Yes.
> At any rate, what can you learn from either a positive
> or negative result? With your test, if one of the tests stain, but not
> the other, can you answer the question you set out to answer? I would
> submit that you really can't answer either question 1 or 3 that I listed
> above. You do get some indication about question 2, but it is hard to say
> that it was simply the dichromate that caused the effect. Could the
> exposure have also played a role in the staining?
You mean expose the paper to UV light with no added emulsion? That would
be a 2nd variable, and certainly a good one.
> What about the water> development?
The paper that stained was rinsed in water immediately after glyoxal, and
when I discovered the stain given another long soak ... So if the water
development *prevented* the stain, it did so in some as yet inscrutable
way.
> One particularly odd thing is that you are simply ignoring environmental
> conditions. If these have any bearing on the staining you get no
> information about it. This is one of the reasons why your tests may not
> give the same results in someone else's lab.
I've heard of the staining "elsewhere," but my only modus operandi is in
my own environment. I'm not operative in any others.
> Also you say that the strip that were under some paper on your desk
> yellowed whereas those in your file didn't. Any reason why you discounted
> the possibility that something in the paper laying on the test strips
> didn't contribute to the staining?
It was the same paper, which didn't happen to have been hardened yet,
though some of it was gelatined.
>
> > One variable, right?
>
> No, and what's worse you really haven't indicated what your supposed one
> variable is? What I'm counting off hand are:
>
> Paper substrate
> strips covered by paper or not
> Type or brand of gelatin sizing
> Pigment type or brand if any
> dichromate type (ammonium or potassium?)
> exposure
> development water (distilled or tap?)
> environment (lots of variables - illumination, temperature, etc.)
All are constant (though my paper that stained was probably dimly lit, my
student's paper that stained was in a drawer) except the weather changes,
but some of the non-stainers are years old, done in all seasons. The only
*pigment* involved is on the exposed and developed strips in the folder,
which did not stain. Since these run the gamut, probably 50 colors on 10
or 15 papers, & several gelatins, I discount those factors.
> I'm sure we can look at this longer an come up with more, but the point is
> that your simple test isn't really that simple. I'd guess that you are
> using the same paper type for all strips, that everything is sized with
> the same gelatin, that you've only chosen one dichromate, and that you
> only are using one pigment if any at all? You would be correct to say
As noted, many pigments in the coated strips.
> that these variables are controlled. Of course, by locking these down, you
> get no information about what affects they may have on the staining. You
> have also seemingly ignored several possibly key variables:
>
> other paper in contact with strips
which strips? the uncoated as noted above. The coated stacked with same,
in folders. No difference in whiteness between top layer (in contact with
folder) and interior, only touching each other.
> development water
Sample coated strips developed over a period of several years, with
"available" water. Unless sudden change in water here this year and in
Brooklyn last year, not a likely factor.
> exposure
As noted, same exposure or lack thereof.
> environment
Such as....? Not aware of "environment" changes.
> You can only do that if you can make the case that they are not important
> to the staining process. If these do matter, then you've got a problem.
What you seem to be saying is that unless I have a "clean" temperature -
humidity controlled lab with distilled water, forget the question. Thanks,
but that says give up without a try. Is that your Querulous Variables
Theory (sorry having a senior moment, forgot the term) ? Needless to say,
most of the questions you ask above about variables were reviewed mentally
(though not in public e-mail) & discounted for reasons given.
> That is what I understand about your test. You'll have to correct any of
> my mistakes and misunderstandings before we can look at this much deeper.
Still hopeful, I await your prescription. Meanwhile, I thought of a 3rd
variable. Expose the *stained* paper to a dichromated emulsion. Maybe it
bleaches. Of course I only have two small pieces, about 4 x 5 inches. Have
to deploy carefully. And who knows if I'll get the effect again? Probably
needs several months "ripening" to achieve.
Judy
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