What Borg have you been going to that stores any sheet flat? The ones
around here store their sheets on racks that have three horizontal support
beams. The beams in the middle are higher than the ends. Built in warp.

"Howard" wrote in message
oups.com...
If you do need small plywood sheets and must buy from HD or Lowes, buy
a whole sheet that has been stored flat and have them cut it to the
size(s) you need. Most places will make the cuts for free or 50 cents
each. Compared to the cost for warped but smaller sheets you are even
or ahead.