Philippe,
there is an extended article in www.grupponamias.com/index_en.html (see the "articles" section) on cyanotype. The translation into English needs to be reviewed, bur the content is still good.
Prussian and Turnbull blue go through the same intermediate, KFe[Fe(CN)6)], and the ferric ferrocyanide is thermodinamically more stable than ferrous ferricyanide (see the referenced in that article). So, though I never made a direct cyanotype, I may argue that the two blue are the same.
Alberto
P.S.: the site has recently been updated with much more images, and some articles and recipes.
>
> Note that my question was more about the aspect of the two blues. Are they different in tone or stg ?
> The idea behind using positive cyanotype is to avoid enlarging negative. Just enlarged "inter"positive would be sufficient in this case.
> I'll give feedback to interested people.
>
> Thanks,
>
> Philippe
>
> On Wed, 5 Nov 2003, Monnoyer Philippe wrote:
>
> > Hello,
> >
> > I'd like to try reversal (positive) cyanotype which gives Prussian Blue (ferric ferrocyanide). Before ordering potassium ferrocyanide I would like to ask you guys how Prussian blue compares to the common (negative) cyanotype Turnbull blue (ferrous ferricyanide).
> > Is it colder, deeper, ... ?
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Received on Thu Nov 6 05:50:30 2003
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