Re: mordancage

["Christina Z. Anderson" <zphoto@montana.net>]

<snip from Judy>
> It isn't clear to me why it's necessary to search for bomb grade peroxide,
> or anything stronger than drugstore for that matter -- simply "adjust"
> the strength of the bleach by increasing ratio of peroxide to water. That
> is, more peroxide, less water equals stronger mix.
>
Judy,
     Conceivably you are correct, except in the Coote formula part A is a
certain amount of copper chloride, acetic acid, and water, stored in a
bottle separate from the h.p.  The h.p is added at time of bleaching--no
extra water is added.  Conceivably you could lower the amount of water in
solution A but why?  20v or 40v h.p. is readily available.  I only bought
the 135v to save space--it's in a liter container and mixes up to quite a
batch.
     I think in your formula (and maybe Jon's) you mix everything up at the
time of use--like, add a little acetic acid and copper stuff to the hp and
then that would work.  The Coote formula I keep in a brown jug and don't
have to carefully measure out anything at time of use--just a cup of the
bleach formula and a cup of hp (no mls and scales to worry about upon use).
I, in fact, had mixed this last batch up well before the start of the
semester, and it worked great 5 or 6 months later.  I don't know if that
would be the case if my formula called for h.p. being mixed into the other
stuff at initial time of mixing.
>
> Metallic silver is the BLACK part of a developed photograph. The
> highlights (whites) have no metallic silver, hence no action.  In the
> bleach and redevelopment method the entire photograph is removed, and the
> silver halide remaining (before fixing) is then developed up -- in reverse
> of the first print, of course.
> Judy

Yes, this is true if you bleach and redevelop before fixing.  If you fix
first and then do the mordancage, or use leftover prints from years ago, the
bleach does not remove everything, only the darks, and you still have a
positive, NOT reverse image.  The darks are eaten away and may look
solarized and funky now that they are white, but the original print
highlights are just the way they were before bleaching.  For instance, the
nudes I did today have the bodies totally intact except where there may have
been a really deep shadow, or pupil of the eye, or armpit hair--those areas
got eaten away.  But the image is still positive except for those funky
spots and drippy nipples.  Maybe it is clearer if I say the original print
highlights and *midtones* too  are as per normal...
Chris
>