I just recently purchased one of those wool ironing mats AND a clapper and use both together. I lay the mat on my ironing board. I just finished two quilts using BOTH of the items, holding the clapper in place about 20-30 seconds and the fabric is so flat. that you almost can't see where the seams are and looks like a cheater print. I am so happy that I invested in both those items and yes, they were spendy but probably the best items I have ever used in quilting. Oh, don't buy the small mat, you will be disappointed. Get the 17x24. Good Luck.