How to use duplicate stitch to mend knit fabrics like socks, sweaters, etc, whether handknit or commercially knit.
Use this method when the structure of the knit fabric is still basically intact. When you either have a tracery of the original yarn/thread still in place or you can see that there is only a broken thread and the stitches around it missing.
Mending kit available at: shop.miriamfelton.com/