"Norman Worth" wrote

I use a motorized drum dryer for my FB prints, and they come out nicely
flat. Unfortunately, in this dry climate, they don't stay that way. In a
couple of months they wind up quite curled.

Is there a back treatment which will counteract that curl? Is mat
board the only answere?
I partialy air dry then blotter dry using hydrophobic separators
which alternate with A flute corrugated board. I think a twelve hour
dry about
minimum. In a few days I've a little curled print. Not at all wound up
though.
Blotter books should be banned. They give blottering a bad
reputation.
Go with corrugated, A flute is best.
Dan