duotone cyanotype VDB

Good morning all,
I love to post on the weekends because it seems everyone is out and about
doing other things than posting and the airwaves get very dull..

My last assignment the students did was duotone cyanotype/vdb, either one
below the other. It was a very experimental assignment, to be sure, because
the two processes don't really like each other--the potassium ferricyanide
in cyanotype bleaches the silver in the VDB, and the VDB bleaches the
cyanotype or takes over so much that the cyanotype disappears.

We found out a number of things--that's what's so nice about having 15
students, it's like doing 45 tests yourself--1. misregistration actually
looks good! 2. And one student returned the print to acid of some sort
(citric I think) and the cyanotype came back, which seems to prove the
alkalinity of the VDB and fixer bleaches the cyanotype but doesn't remove it
completely. 3. AND several of the students used a mix of gesso, acrylic
matte medium and water in equal parts between the layers of VDB and cyano
and that worked well. 4. A layer of gelatin between is less effective. 5.
All got better results when overexposing each process. In fact, one of my
favorites was a totally brown overexposed print that you could hardly see
the image, painted over with cyanotype which immediately bleached the image
up to visibility, and then exposed. 6. If you don't make sure to rinse
well after all processes and return to an acid state the alkalinity of the
paper, either from fixer or vdb or what have you, will creep in lavender.

Most of the prints were of the "alternative" alternative variety, in other
words, loosey goosey. I do have them scanned...and if and when my website
is finished (grrr) I can post them. So if I were to do this warm/cool thing
and want a perfect print it would be best to do the cyanotype/palladium I
think (or palladium/gum).

I would love other people's experiences on this shared here...what have I
missed?
Chris
Received on Sat Mar 4 10:15:58 2006