Buttonhole stitch and the related blanket stitch are hand-sewing stitches used in tailoring, embroidery, and needle lace-making. Buttonhole stitches catch a loop of the thread on the surface of the fabric and needle is returned to the back of the fabric at a right angle to the original start of the thread. The finished stitch in some ways resemble... Found on http://en.wikipedia.org/wiki/Buttonhole_stitch