An overlock stitch is a special type of stitch that simultaneously sews fabric, trims its excess edge, and finishes it, thereby preventing the material from fraying. It is created on a machine called an overlock machine, which, unlike a classic sewing machine, works with multiple threads, usually two to five. Instead of a bottom bobbin, it uses a system of so-called loopers that interlace the threads and create a characteristic looped binding encompassing the edge of the fabric. The result is a flexible yet strong seam with a professional appearance, such as can be seen on the inside of most ready-to-wear clothing. Due to its elasticity, this stitch is particularly suitable for sewing knits and other stretchy materials, as it can stretch along with the fabric without breaking.
