When I'm sewing and pressing away from home I always miss my clapper. I'm a chain piecer and will have one piece on the machine, one piece under the needle and one under the clapper. My seams are nice and flat without fussing with starch. I don't use the clapper for longer seams because I don't have the patience to wait for each bit to flatten. With a wool pressing mat on the bottom and clapper on top, no pressing problems.