Duplicate Stitch, or Swiss Darning as it is sometimes called, is a decorative stitch usually worked over stockinette stitch. Its basic concept is in its name: You sew over your finished knitting with a contrast color, “duplicating” the original stitches. It’s easier than Fair Isle or intarsia, and best of all, Duplicate Stitch can be an after-thought, when you think you’ve finished something and it’s just not quite enough!