U of S | Mailing List Archive | alt-photo-process-l | Re: Printing gum with little pigment

Re: Printing gum with little pigment

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
less 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
> extended 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 concentrations. 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
> 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