U of S | Mailing List Archive | alt-photo-process-l | Re: Taming Fabriano Artistico (Trad. White) for Cyanotype

Re: Taming Fabriano Artistico (Trad. White) for Cyanotype



3 Aralık 2008, Çarşamba, 5:10 pm tarihinde, Christina Z. Anderson yazmış:
> Ammonium ferric citrate (why is it written this way--can it equally be
> written ferric ammonium citrate or is that a chemistry no no?) has bigger
> molecules than  ammonium ferric oxalate and hence is harder to absorb in
> the
> paper so I have been told (not being able to see it with my eyes :)) but I
> have not personally had a problem with bleeding although I certainly do
> see
> blue water from washoff.

I observed this. The paper absorbs New Cyanotype sensitizer much easily
compared to Trad. Cyanotype (or Argyrotype and Vandyke)... I haven't had
bleeding problem either, except for one case I was using CP Canson
Watercolor paper...

>
> What do you mean by "peptization" Loris?

IIRC, it's the case when the Prussian Blue particles form / become too
small (nano scale) / won't form strong lattices, so they won't get trapped
inside the paper fibers, they will leach out (bleeding) instead.

> And is there a conservation difference in paper that has been treated with
> HCL vs. oxalic acid, I wonder?  Or have I watched too many horror movies
> where someone's face melts when acid is thrown on it?

Well, there will be definitely some weakening unless you're careful / you
use too strong concentrations. But if one manages to get it out of paper
it won't continue to cause further problems methinks. We have examples of
vintage Pt/Pd prints which were presumably cleared in HCl. (Once upon,
that was a widespread procedure IIRC...)

> ...
> I find it fascinating that cyanotype is so versatile.

Me too.

Regards,
Loris.