From: Judy Seigel (jseigel@panix.com)
Date: 11/09/00-03:45:08 PM Z
On Wed, 8 Nov 2000, J. Wayde Allen wrote:
> On Wed, 8 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.
>
> Yes to which?
All.
> > > 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?
>
> No, you said that you were exposing your test strip. Could this exposure
> you are doing have an effect on the staining?
As I said yesterday, the fact that the non-discolored strips were exposed,
the discolored ones not, was a (single) variable it occurred to me to
test.
> I lumped that in as an environmental factor. In other words, I would
> consider the ambient illumination where you setup your test.
Same studio light for all.
> > 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.
>
> OK, but is it possible that it has an effect or not? Maybe it simply
> washed out the Glyoxal? Maybe there is something in the water that
> combines with the Glyoxal to either cause or inhibit the stain?
ALL paper is rinsed after the hardening, what discolored & what didn't.
If you mean was there something in the water the day the "discolored"
paper was hardened.... has to have been same thing in Brooklyn last year.
But maybe it's in the water again today or tomorrow. Who knows?
> OK, but do you even consider changes in your environment? You also do
> tend to share your data with others, and have complained on more than one
> occasion that these data for your tests often aren't repeatable for
> others.
What kind of changes in *MY* environment over a 6-month period do you
suggest?
As for results not repeatable for others, that's probably because they
work with different ingredients, one or many. Of course "mileage may
vary." But I'm not aware of cases where we're used identical materials in
similar conditions with quite different results -- usually it's a matter
of temperament, as in I can't bear to do TWO coats of gelatin, or SHE
can't bear to stand around developing drop by drop, or HE wants a rough
arty paper, etc.
> > It was the same paper, which didn't happen to have been hardened yet,
> > though some of it was gelatined.
>
> OK, that helps. Were the test strips completely covered, or partially
> covered?
Covered with the emulsion? Partially. The plain paper edges were not
discolored.
> Did the staining occur only under these sheets or where they may
> have been exposed?
All (actually "all" is two pieces) were under other sheets.
>In other words, is there something here that you can
> use to eliminate a possible variable such as exposure to ambient light, or
> is there a possibility that this created the conditions for a chemical
> reaction. Trapping of Glyoxal vapor perhaps?
My other proposed variable test (at this point) would be putting gelatined
glyoxalled paper in different storage for 6 months to see what/if any
discolors.
> > 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.
>
> You can't say that "all are constant" and then cite exceptions. The way I
> see it:
> OK, but did you expose the so called blank strip that had no dichromate in
> it?
Did you read my e-mail of yesterday? I propose to do that.
> > Is that your Querulous Variables
> > Theory (sorry having a senior moment, forgot the term)?
>
> OK, if you are taking this as quarreling, that was not my intent. You
Oh pshaw, Wayde, I'm just being a bit flip.
> > 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.
>
> What reasons given?
Again, for 8000 or so bytes of description & reasons given yesterday.
> I do need to know what you are trying to determine. So
> far that is the most important question that you have not answered. If
> you did I missed it.
I want to know why some paper discolored and some didn't. That wasn't
clear from day One?
> My prescription, if it must be called that, would be is to define what it
> is you are really trying to test, and then identify all of the possible
> variables that might affect your test. Heck, make a list of them. Then
> you can at least identify which ones you can and want to control, and
> eliminate others if you can explain why they aren't important. There is
> nothing magical here.
Well, again, thought I just had, was, did.
> In this case, it looks to me like you have a staining problem but don't
Wayde, if I said "duh" here, you'd think I was being "argumentative," so
I'll say, "exactly." Tho not a "problem" so much as a question. It's
something that happened ONCE. But your asking repeatedly about points
already made, or information already given, is making me querulous.
> really know what is causing it. What I think you need to do is try and
> list all of the variables you think may be causing the problem.
Again, excuse me, thought I had, in response to your questions yesterday.
> If you've
> got only a very few variables by all means run all permutations of these
> variables. That works fine. If however, you've got a good number of
> variables to test. You probably need to resort to a screening style,
> multi-variable experiment. The whole point of such a test being to
> identify those factors that affect your response (cause staining in your
> case).
Obviously. That's what I thought we were discussing.
> One final point to consider is that the so-called scientific method is
> based on repeatable results. If you have tests that are not repeatable in
> different labs, you can't really say that you understand or even have a
> valid test.
My goal is to do art, not publish in Science magazine. If I'm valid in my
lab, that's enough. If different labs get the discoloration, let them
e-mail & I'll share my findings.
Judy
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