I mainly use flannel for the back of my quilts. I always buy at least a foot more than I know I need- for one reason, it will shrink. It is loosely woven so there is no doubt to me it will shrink the other is in case it is off grain, And I wash it in warm or hot water, then dry it medium. A lot of people will tell you to wash and dry it a couple of times - I don't because almost everyone I know is going to wash the quilt in cool or cold water then dry it on low. So I am not worried there will be more shrinkage - it has never been a problem for me anyway. When I put it together I do do spray baste - so much easier - and I do pin every 6 inches or so. And after it is quilted or tied then I put the binding on and I do sew the binding on twice around, usually using a tighter stitch because I hand sew the binding on the back.