coverstitch

Coverstitch, or cover stitch, is a stitch type used mainly for hems and edge finishing of knit fabrics. It is produced by a specialized coverstitch machine that uses one or more needles in the top thread path and a looper beneath the fabric. The resulting seam consists of a straight, neat top line and a series of parallel chain stitches on the underside, which gives the seam exceptional elasticity and a clean look on knits. The setup typically uses 2-, 3-, or 4-thread configurations, producing variations in the number of top stitches and the strength of the seam.

Unlike a standard overlock, a coverstitch machine does not trim edges and is designed primarily to finish hems and seams on knit fabrics. The bottom shows interlocking chain stitches, while the top provides a flat, elastic finish. The machine feeds the fabric with differential motion to minimize stretching or distortion, making it well suited for stretchy garments.

Common uses include hems on T-shirts and other knit garments, cuffs, necklines, and decorative topstitching. It is favored for its ability to extend with the fabric, producing durable, flexible edges without curling.

Care and materials: Use stretch-friendly threads (often polyester) and ballpoint or jersey needles; adjust tension for fabric weight. Coverstitch seams can be more visible on heavier knits and may require testing to achieve the desired appearance and stretch.