The most common type is the lockstitch, which consists of two threads that are intertwined like a twisted rope, with the intertwining point in the middle of the sewing material. From the cross-section of the stitches, the two stitches are like two locks locked together, so it is called a lockstitch. This type of stitch is used for sewing materials such as cotton, wool fabrics, or leather with low shrinkage, and the front and back sides have the same shape, like a dotted line. The stitches are densely distributed, and the sewing fastness generally exceeds that of hand sewing.
Chain stitches are formed by the self-connection or interconnection of the thread loops of the stitches. Commonly used ones are single-thread chain stitches, double-thread chain stitches, and three-thread overlock stitches. The characteristic of this stitch is that it is elastic and can expand and contract with the sewing material without breaking the stitches. It is suitable for clothing made of thread elastic fabrics or products and clothing blanks that are easy to loosen the overlock.
