I actually was not able to read and concentrate on alt for a few days, so I am coming back to all the postings. I am actually examining my test prints not their scans so I have an advantage here. Once again my conclusion is that contrast (the amount of visibly separated steps on the test tablet) is not dependent on pigment concentration. I would also conclude that amount of pigment and exposure are not correlated, both high and low pigmnet concentrations end up with the same exposure for best results.
Testing pigment concentration, exposure and dichromate concentration could be a wonderful set of experiments to explore in a clasroom setting. The students are not biased and a number of experiments can be done at the same time.
Date: Fri, 16 Jan 2009 16:33:24 -0700
Subject: Re: Printing gum with little pigment
I did this years ago and cannot find that I photographed my wedges tho I did for all other things I did, so I'm on it again. I'll do it and let you know. The more of us that test it the more we can see if it is quantifiable. I have 3 31 step 4x5 wedges so I can do 3 side by sides same paper, same drying time, same everything at once, just by cutting pigment in half and then again, does that sound good? The adage is that less pigment/longer tonal range and more pigment/shorter tonal range but I have always wondered if, in fact, the shorter tonal range was due to choosing the same exposure time for a darker pigmented layer that would in turn therefore (since it might require more exposure) produce a shorter scale--which, in theory is not really a proof of longer tonal scale. So one would have to make sure to overexpose the step wedge on both accounts so that there would be at least 2 blocked up steps merged at 1 to make sure maximum
black is achieved.
The deal is this, though: Sookang Kim's gums are NOT beautiful because of some technique, IMHO, they are beautiful because 1) she has chosen effective subject matter and 2) she has mastered the process with, I would assume lots and lots of practice. it's like someone who is a concert pianist--I'd love to be like them but when it gets down to it, do I want to devote hours and hours per week of practice? With gum, yes, with pianos, no.
I don't think there is a Holy Grail of gum nor a Holy Secret...but damn her prints are gorgeous. What I like most about them is that they are simple and simply lit. Like the tea bag. I, too, am very seduced by large size, and actually very seduced by maestros of any process.
Now she might just prove me wrong and say that she only does a couple gum prints a year and my theory is shot full of holes, but I doubt it.
BTW I've had a couple people tell me Livick no longer does gum--is that really the case?
----- Original Message -----
Sent: Friday, January 16, 2009 4:05 PM
Subject: RE: Printing gum with little pigment
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.
> Date: Fri, 16 Jan 2009 22:01:40 +0200
> From: email@example.com
> Subject: Re: Printing gum with little pigment
> To: firstname.lastname@example.org
> Thanks for sharing these Marek.
> I regularly print gum from negatives calibrated for Cyanotype, something
> like log 1.5 ES (= 15 steps with the 31-step tablet - each step = log 0.1)
> using weak / weak-moderate pigment concentrations, getting full detail
> starting from shadows up to the highlights. So I definitely believe in
ss pigment = more range -> it's in parallel to my experience...
> 16 Ocak 2009, Cuma, 7:33 pm tarihinde, Marek Matusz yazmış:
> > Hi all
> > I was waiting for a dry spell to bring this up. A while back Judy made a
> > statement that printing gum with little or no pigment allows for a very
> > e xtended range. I looked back through the Post Factory issues and really
> > could not find examples. Hey Judy thanks for sparking my interest.
> > Since I was messing around with the post-flash and was getting good
> > results in extending tonal range of the print I decided to do some
> > experimentation and actually print some test prints.
> > http://picasaweb.google.com/marekmatusz1/ExtendedGumRange#
> > Two sets of tests are done with same water/gum/dichromate but different
> > pigment concen
trations. I have made different exposures and tested two
> > development times. I used indantrone blue which is a wonderful dark blue
> > and non-staining. I can not see that low pigment concentration extends the
> > rane of gum print, to the contrary it allows less steps to be separated on
> > a standard step tablet. One of the tests is also a good illustration of
> & gt; how delicate highlights with dark shadows can be printed with the same
> > negative with the postflash.
> > Anybody else want to chime in. It would be great to see some
> > illustrations. A picture is worth a thousand words.
> > This contrast vs. pigment issue has been on my mind for a while.
> > Marek
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