On Wed, 8 Jan 1997, Kevin Crombie wrote:
> I had always understood that while hydrogen peroxide "intensifying" is
> useful for test strips (for those of us unable to judge how a print will
> look in a week) it affects the long term life of the print, i.e. shortening
> it considerably.
>
Kevin I've never heard that, or seen it,and can't figure why it should be
(though as we know chemicals are devious and invisible). My understanding
of what happens is that the extra oxygen in the H2O2 oxidizes the print
immediately as would otherwise take place naturally in air over time, so I
don't see any harm there (like an overdose of growth hormone). We also
give a brief rinse after the H202 as well.
As for showing how the print will look "in a week", peroxide has its
limitations anyway: for one thing, the *wet* print is in fact richer and
deeper in color than the dry print is going to be, as is the case in every
medium. But in my experience you get probably 80% of the final depth of
tone right away simply by hairdryering the test strip. (We don't forced-
heat dry wet emulsion, but there's no problem with wet print.)
Since the dried test strip will also show the shadow separation more
accurately than the wet one, it is actually a more useful preview. You are
then free to believe that the final dried print will in several days
be even a little bit darker -- but don't depend on it.
Judy
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