Wool Pressing Mat 17in x 17in x 1/2in ThickPress any pieced or embroidered block with ease. The density of this high quality 100% felted wool mat localizes heat to the seams and stitches, effectively pressing both sides at once. An added bonus? The texture of the wool stops fabrics from shifting so there is no distortion when pressing. Tips and Tricks For best results, use a dry iron when pressing. When pressing an embroidered block, iron on the wrong side. The wool mat will cushion the