U of S | Mailing List Archive | alt-photo-process-l | Re: was Miracle size for gum now tonal range

Re: was Miracle size for gum now tonal range

That's an interesting bit of information. I tried once or twice to
clear (in 5% sodium metabisulfite) but it didn't made a difference -
at least one that I was able to perceive, therefore I left the
practice. Perhaps the extra darkening I get isn't as strong as those
people were experiencing back then...

BTW my exposure times aren't that long, 3 - 5 minutes with 5% AD under
UVBL light and Pictorico (old original stock, not new stuff) media.
For comparison, my standard exposure time (using the same
transparency) is 6:30 for 2A(20%)+1B(8%) trad. cyanotype and 16:30 for
1A(25%)+1B(12%) trad. cyanotype. (As a side note: I like the darker
tones I'm able to get with the new-to-me formulation but the printing
times are annoyingly long as you can see above...)


2009/10/10 Christina Z. Anderson <zphoto@montana.net>:
> ...
> FWIW I never clear, only step wedges when I am trying not to get a false
> exposure read.  But it's funny because at one point in the late 1800's
> people were panicking because their gum prints faded over time and found out
> they were relying on the dichromate stain in the shadows to provide some
> print density when, in fact, over time in sunlight it does bleach to a pale
> sage green.