I got some paper birch after it was freshly cut. I cut and sealed the blanks, and after about a month, I rough turned a couple of the blanks to about 10% of finished dimension. I soaked them in DNA and put them in a paper bag as usual, only this time I filled the bag with shavings and burried the rough outs in the shavings. A month later when I opened the bag the platter and bowl HAD warped and shrunk so much that a re-turn is pointless. Should I have waited longer for the blanks to dry some prior to the rough out, or is this just the nature of birch? If I should have waited, how long? Is there a need to wait a certain length of time with any green wood before roughing?