Re: BL light box 'blues'
'OK, now let's go back to what Ken said....below.
My VDB exposure times are way less than cyano....maybe 5-8 minutes at best. My bulbs may not be 5" from the print, but they aren't too far off from that, and no inverse square law. I think this is fairly consistent across paper types, two exposure units, and 18 students per semester.
And that is low humidity in BZ in the winter/spring.
The only way to really determine if it is a neg prob is to print a Stouffer's alongside....hey Ken do you want to mail me a neg and I'll print it up by a Stouffer's for you??? If they print fine for me, then I might suggest a problem with your exposure unit?
btw I can print them in gum as well...
hoped... Cyanotypes seem to be requiring around 40 to 50 minutes while I have not