Thanks to the collective wisdom of the list, and a few days of concerted
effort on my part, I've just completed my first successful group of
monochrome carbon images. There are a number of refinements that still need
to be made, but these initial results are very gratifying.
As a test, I tried several exposures using digital negatives designed for
platinum printing. The results are promising. Adjustments need to be made
to the platinum curve, but exposure times appear to be consistent from one
negative to the next.
I would appreciate some clarification concerning the clearing/hardening
steps of the process. Some texts mention a clearing bath of chrome alum,
while others suggest that alum may be detrimental to the archival properties
of the print. "Keepers of Light" suggests sodium bisulfite or potassium
metabisulfite instead of the alum. "Keepers" also suggests that formalin
may be used as a hardening agent, though a hardening step is not really
necessary. M.Nadeau's text indicates that a hardening bath is a necessary
step.
These first prints are merely tests on fixed out silver paper. They needn't
last as long as the pyramids. But as I experiment with other papers , I
would like be interested to hear procedures used by other list members for
clearing/ hardening baths.
Thanks,
Tom Hawkins