> Someone told me that they'd heard that Cyanotypes and Van Dyck (is this how you
> spell it?!)prints were less permanent than other types of Alternative Processes.
> Is this true? Is there a kind of league table of permanence? How do the various
> alternative processes compare with selenium toned silver gelatin fibre-based
> prints?
I have 100 year-old cyanotypes that are still as dark as the day they were
made (don't ask me how I know). I think Ginger points to the major risk,
which is sunlight (and sun-faded cyanotypes do come back part way in the
dark), but if you look through baskets of old prints in fleamarkets, the
cyanotypes (if you're lucky enough to find any) are usually still bright,
certainly much less faded than the silver prints.
Van Dykes (which is how I see it spelled as a rule) are more problematic.
Mike Ware argues that they're not very archival at all. I've had some 15
years unchanged, which of course is but a moment in art. My guess from
student work is that the processing makes a great difference -- probably
the archival wash.
Judy