I have some serious doubts about how well Van Dyke sensitizer will
last once it is mixed. Lets see if anyone else on the list has had
any experience with this. Judy has had some luck keeping sensitized
cyanotype paper so maybe she has the answer to this.
Bob Schramm
Bob - At the Southwest Craft Center we've been using Van Dyke Brown
Sensitizer, made according to a recipe similar to the one you posted
earlier. We have a bottle over a year old and it works great. We
recently made up a new batch which responds similarly to the old one
except for minor speed and contract variations.
Carl Bohne
San Antonio, TX