Wow, I have run into the EXACT problem... only diff is I'm souping in D76 1+1. (AP400)
I haven't remembered ever having the cut corners tear my printfiles but it sure is doing it now.
I was coming to the conclusion it was the dry conditions here around DC but not sure. (drying in shower stall/no heat)
At least I have a use for the 1964 collection of Encyclopedia Britannia.
2 volumes seem to be enough to flatten after 24 hours or so but dont know for sure if they will stay flat as this issue has only recently reared it's ugly head.
edit: I should correct myself after reading more thoroughly
I'm having cupping issue not curl like some 120 rolls can do.
I hang clothepins with a penny or 2 tape on them for weight.
CUPPING is probably the more appropriate term for my problem.

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