If you have fusible batt then you can iron the sandwich together. I get a smoother sandwich if I can iron it flat. A big table covered with a protective cover like a mattress pad will work. I use the old carpet in my basement to lay down the backing, smooth out the fusible batt on top and then center the top on the batt and the backing fabric. I find that an inch all around is good. I iron the top well and that is enough to stick the sandwich together with the Hobbs batt. I then flip to sandwich over on the carpet and iron the back well too. The Hobbs allows you to peel it up if you have any wrinkles and re-iron it in place. I usually place a few safety pins around the perimeter in case I catch the edge when I FMQ the quilt to prevent peeling up the edge. Caution: Hobbs fusible batt is water soluable so don't have water in your iron or use steam.