This Riley Blake Notions 12in Tailors Clapper is made of hardwood and is a classic tool used with a steam iron to set a seam. 12” Hardwood Tailor’s Clapper will make perfectly pressed seams for quilting or sewing. Use it on quilt blocks or garments for seams, creases and pleats. Press your seam with your steam iron; then, apply the tailor’s clapper and firm pressure to set the seam.