Whipstitch definition in American English Backstitch is a needlework technique which involves creating small zigzag stitches with the purpose of securely fasten two material pieces together. This technique adds strength and avoids the material from fraying. The whipstitch may be used for a variety of stitching projects, such as finishing the edge, sewing appliques, or even making quilts. It offers a neat and expert look to the completed product.