Teach Yourself Visually Knitting

You should hold yarn A, the weaving yarn, in your right hand, English style, and
yarn B, the working yarn, in your left hand, Continental style.

1 Insert the right needle into the next stitch as if to purl. Bring yarn A under
the right needle from front to back; then lay yarn B over the tip of the right
needle from front to back.

Color Knitting

chapter 10

2 Bring yarn A back to the front—to where it came from (it will be hooked
around yarn B)—and then draw yarn B through to purl the stitch.

3 Hold yarn A down away from the needles and purl another stitch using
yarn B.

Weaving In, Purl Side: Working Yarn Left, Weaving Yarn Right