1. Rives BFK in beige (or whatever the color) has something, resin or other
substance, in the fibre that inhibits absorption. It will not even
take enough cyanotype to make a print. For a toned paper, try
dye-it-yourself. (Someone on this list may know an archival one. I've
used tea and coffee, but they tend to fade in light.)
2. Since cyanotype, VDB, gum, etc. have a *different* set of allergies,
and are done in any studio-type room by regular room light (as long as
paper is dried in the dark), you might consider one of them instead of
darkroom.
3. Sandy's story prompts another reminder to all you
young-folks-who-think-you're-immortal: Once you get the allergy, it may
be too late. Keep hands out of liquids. Keep trays covered when not
actually going in and out. (Even a piece of corrugated cardboard cut to size
makes a BIG difference in fumes in the room.)
4. Sandy says darkroom is ventilated, but where are the outlets? If
they're at a height that pulls vapors from tray past your face they can
be worse than useless.
PS. I've heard much praise for Sprint.....
Judy