Originally Posted by Prism99

I would have heavily starched the flannel first (before cutting into strips). Then it would not distort while you sew. You can still do this on the strips you have cut but not sewn. I use a large wall painting brush to "paint" a 1:1 solution of Sta-Flo liquid laundry starch and water onto fabric. For yardage I toss into the dryer, then iron with steam. For your strips I would just hang them to air dry, then iron with steam. (They would come out a mess if tossed in the dryer.)

Oops. Just re-read your post and realized you are trying to sew rag quilt strips together. In that case, you might be better off using several layers of spray starch on each side of each strip. Lay out a large sheet to catch any overspray, and air dry (or speed drying with a hair blower) between layers of starch. Put extra layers of starch on the flannel side. This should help stabilize the flannel so it doesn't stretch while you sew.

Also, on your machine are you able to adjust the presser foot pressure? Easing up on that might help too.