odd cyanotype behavior

     Locally there are several brands of inexpensive, good quality cold
pressed watercolor paper available. However, I usually prefer the smoother
surface of hot pressed paper which is, at least where I shop, only available
in large (and more expensive) sheets. I tried a paper called #234 PARIS
BLEEDPROOF PAPER FOR PENS BY BORDEN AND RILEY. After a couple of test
prints I made what looked like a perfect print but I was called away and let
the print soak for about an hour. When I returned the print had faded
drastically and lost all its blue color, leaving a gray image.
    I soaked a print on a different paper that long and longer with no loss
of image so I assume it is something to do with the paper. Has anyone ever
noticed this kind of behavior?
     Very preliminary tests indicate that the pale gray image might tone up
to a darker image in one or more of the common acids. Any thoughts?

Charles, Portland Or.
Received on Wed May 25 16:28:24 2005