Have never had that problem with the batting. On the other part of your question, I usually leave about two inches of batting on the side edges and about three inches at the top and the bottom. What its all about is that I prefer to lap the edges of the lining over the edges of the top and make a small turn under and pin. Then I use a decorative stitch on my Bernia and it forms a border on top. I really hate to do binding.