Sounds to me, Tom, like you're breaking your own rule: changing two
variables at a time.;- )
For what it's worth, the processes I've tested or seen tested -- Vandyke
brown, kallitype and cyanotype -- all do much better, that is, better
d-max, better tone separation, airdried without heat.
As I mentioned a while back, you don't need a size for VDB if you airdry
without heat, and there is much less random bronzing of the shadows.
Gum shouldn't be heat dried, period.
It's a tossup on double coating, we've found, depending on the paper. A
smooth shiny paper can actually lose density with a second coat, which
wipes off the first coat.
cheers,
Judy