Wow. Thank you for this post. As a longarmer, I can attest that you know whereof you speak. But I did not know that wavy borders could be caused by not prewashing/drying/pressing the fabric. I thought the only cause was not measuring/cutting the border strips before sewing them on. I also did not know that when prewashed fabric "shrinks", it is actually not shrinking at all, but just returning to it's unstretched size. Thanks so much for this information.