Re: Printing gum with little pigment
Marek, I found another step print with Prussian, more concentrated
than the other two, and added it to the visual. It also printed
exactly 7 steps, just as the other two did. As I said before, these
are just three isolated strips, not a planned or controlled
experiment, but as a supplement to your data, they seem to add to the
chorus. I also added reflection density readings for the three
strips, in case anyone is having trouble with the idea that there's
no correlation between # steps and tonal range for gum. This has got
me thinking and scratching my head, but sure darn interesting.
Thanks for asking the question,
Oh, here's the link again:
http://www.pacifier.com/~kthayer/html/pigcomp.html
P.S. I decided not to upload those other strips I mentioned, with the
overpigmented pthalo; since they addressed a different question, I've
decided they'd just be confusing here.
Katharine.
On Jan 22, 2009, at 9:26 AM, Katharine Thayer wrote:
You're welcome, although I'd caution that this is just two
unrelated step tablets that I pulled out of a box that happened to
be made using the same pigment at different concentrations, not
anything that could be called a proper test. I wouldn't put too
much weight on it, but yes, these two step prints do seem to
support your observations. Like you, I wish more people would
provide actual step prints with exposure and development info, to
add to the database of information on this rather fundamental
question.
Katharine
On Jan 19, 2009, at 5:40 PM, Marek Matusz wrote:
Thanks,
This is exactly was I found and was trying to illustrate and
totally agrees with my observations. I was hoping more people
would chime in with their illustrations on the subject.
Marek
> Date: Sat, 17 Jan 2009 17:25:15 -0800
> From: kthayer@pacifier.com
> Subject: Re: Printing gum with little pigment
> To: alt-photo-process-l@usask.ca
>
>
> On Jan 16, 2009, at 3:05 PM, Marek Matusz wrote:
>
> > Loris,
> > Here is where the argument breaks down. What you consider a weak/
> > moderate pigment I might be using and defining as strong. The
only
> > way for you to convince yourself of the validity of your
assumption
> > is to cut the pigment concentration in half or quarter and print
> > something side by side. I am looking for people that have done it
> > already and can share the actual prints/test strips.
>
> Okay, this is all I found in an afternoon of searching through
boxes
> of test strips and test prints, that would serve the purpose. It
> would have taken me less time to just go down and print some, but I
> don't want to go down there; it's cold. . :--) Anyway, here is a
> comparison of two Stouffer 21-step prints in Prussian at two
> different pigment concentrations; it is consistent with your
> observations. These would have been exposed and developed in a way
> to yield the optimal DMax and maximum number of steps for each mix,
> per the instructions on my site.
>
> http://www.pacifier.com/~kthayer/html/pigcomp.html
>
> Hope that's useful,
> Katharine
>
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