The overlock presser foot is an additional accessory for a domestic sewing machine that allows mimicking the appearance and function of a stitch created on a specialized machine called an overlock. An overlock stitch is a type of stitch that sews fabric together and simultaneously overcasts, or finishes, its edge to prevent fraying. This foot has a specific design, often with a guide or a small pin over which the stitch is formed. The guide holds the fabric edge flat and prevents it from curling, while the needle stitches the fabric and simultaneously forms loops over its edge. Unlike a true overlock machine, however, this foot does not trim the fabric. For the best result, it is used in combination with a special stretch stitch, which is often labeled as “overlock stitch” or “overcasting stitch” on modern sewing machines.
