Save yourself - don't use 2 layers of batting! Especially if it's W&N! My very first quilt was a double irish chain lap quilt that I was making for my grandmother. Thought it would be warmer for her if I used 2 layers of batting. I did SID in the 'chains' and flower designs in the plain blocks. The plain blocks weren't too bad with the double layer but the SID was painful with a capital P. But who knew? I did get through it with the help of some needle nosed pliers and she loved it so it was worth it in the end but I really don't know that it made it really that much heavier. Several quilts later my SIL said the one I made for them amazed her at it's warmth with a single layer of W&N. She asked me to make a quilt for my niece as her room is frigid in the winter. I used a single layer of W&N and used flannel for the backing. I swear that child will never move a muscle under that quilt!