Alex Anderson is on HGTV's web cite. I watched her on how to pin a quilt to do machine Quilting. The bottom has to be tight and smoth pinning the sandwich has to be pinned every 2" a part. After I watched her I have had no problem with my back. On quilt frames the back has to be tight. If there is some pleating on the top it is from your sewing I have found that out. From doing my own Machine quilting. Check out the web cite. She has a lot of stuff on quilting.