I love Hobbs 80/20 fusible batt. It is dry ironed to the quilt top and back. I iron a larger quilt on the old carpet so it lays full size and flat. I spread out the back (right side down), lay the batt on top and then the top down right side up. I then iron the sandwich together, flip it over and iron the back, fixing any wrinkles and when it looks perfect, I put a few safety pins along the sides to prevent it separating. I start machine quilting from the center and about half way finished, I re-iron the back if needed. Good luck and I have not had any puckers on my quilt backs since I started using it.