I make a lot of place mats for our bazaar and usually use whatever batting I have handy. I very rarely use high loft so that is not a problem as I don't have any in the house. Most of those I make are 13X 18, but have made larger ones as it sort of depends on how much fabric you have to work with. They seem to prefer a set(4) for selling and that limits the size of the mat as I normally use scraps.