Emboridery - Duplicate Stitch:
A duplicate stitch is an embroidery technique that covers a knit stitch with a different color yarn. Because it duplicates a knitted stitch by following the path of the yarn in the stitch, you need to be able to recognize the V-shape of a knitted stitch.
This technique is helpful to avoid intarsia, as Cecily did in Katie Bell's Baby Cardi. Another great use of duplicate stitch is when more than two colors are used in a fair isle pattern. Rather than stranding 3 or more colors along each row, only strand the two colors that are used the most, then when the garment is finished, go back with the other colors and cover the stitches for the third color with duplicate stitch.