Instead of pins i use 501 spray. I lay down the backing right side down, then spray lightly, then lay the batting down and spray lightly. Next the top right side up. I hand smooth all layers. Take to my ironing board starting on back in the middle, I heat set the spray. Working from middle to out to iron the puckers out. Once I have done the backside I turn it over and heat set the top in the same manner. Sure save from all that pinning . This sandwich will stay together for a long time till you are ready to Quilt