A coverstitch is formed by two or more needles which add straight stitches to the fabric and a looper thread on the opposite side of the fabric that zig-zags between the straight stitches. A coverstitch results in parallel lines of straight stitches on one side of the fabric and an overcast stitch on the reverse side.^[1]: 159 It is widely used in garment construction, particularly for attaching trims and flat seaming where the raw edges can be finished in the same operation as forming the seam.