Re: spectral sensitivity of platinum/palladium and cyanotype coatings.

My approach is admittedly not as 'pure' in the sense of trying to find out
which particular ink pair works the best. But I do think there is some benefit
to using black ink to increase the UV transmission density for processes like
Van Dyke and Salt. I have no difficulty at all making negatives with enough
density range to print Van Dyke, which is something I found difficult to do
using the straight PDN approach, especially on the 1280.

One thing I haven't had the time or inclination to investigate is the fact
that the ternary diagram I use has some colors that are 'out of gamut' for
some printers. I suppose this could cause some non-linearity in the
transmission density response as the amount of black ink is varied (By
changing the saturation). It is not something that has yet caused a problem,
though.

The approach I have been using is certainly a 'stone knives and bearskins'
method that may not be the last word in precision, but it works for me and the
workshop students who have used it.

Clay
Quoting "Christina Z. Anderson" <zphoto@montana.net>:
> I'd appreciate your further comments on what you said, though, Clay:
>
> " In the end, it doesn't really matter, since it is trivial to find out
> > which colors are most efficient at blocking UV light for your chosen
> > process"
> :
> Do you think think this is because of your use of black ink in the mix and
> not just pure color? Because if using straight color, it becomes more
> apparent that there are a narrowed few that will work in each
> process...maybe with black ink this is not so crucial? I mean, I've seen
> your pt/pds at APIS and they are gorgeous...
> chris
>
Received on Tue Feb 21 10:10:31 2006