If you have bias in your quilt top blocks you have to take great care while pressing and storing the top. It will grow out of shape it you even put it folded with other quilts on top of it to wait it's turn to be quilted. The weight of the other objects can force a bow into the fabric. I don't know if this is what happened to you without seeing the top. but, just a word to the wise.
Last edited by RedGarnet222; 12-17-2018 at 02:51 PM.