Welcome from Ontario, Canada. If you remember the title of the thread, you can put it in the QB search box. Getting puckers in your backing when quilting are from the backing moving as you quilt. You can heavily starch your backing and the stiffness can help with puckers. You can also make sure the quilt sandwich is well secured or basted a number of ways. There is 505 basting spray, thread basting, safety pin basting, Elmer's washable glue basting and Hobbs fusible quilt batt. A well secured sandwich will shift less when you quilt.