Casting on (knitting)
Long Tail Cast On
In knitting, casting on is a family of techniques for adding new stitches that do not depend on earlier stitches, i.e., stitches having an independent lower edge. In principle, casting on is the opposite of binding off, but the techniques involved are generally unrelated.
Casting on can also be decorated with various stitch patterns, especially picots. The cast-on stitches can also be twisted clockwise or counterclockwise as they are added to the needle; this is commonly done for the single cast-on described below to give it a neater, more uniform look.
Casting on is sometimes done with two needles, or a needle of larger size; the extra length of yarn in each stitch gives the edge more flexibility.
When casting on at the beginning, one end of the yarn must be secured to the knitting needle by knotting it, usually with a slip knot. This knot is unnecessary when casting on in the middle of the fabric (e.g., when making the upper edge of a buttonhole) since the yarn is already secured to the fabric. The original slip knot can also be pulled out (after a few rows have been knitted) without damaging the knitted fabric.
Once one loop has been secured around the needle, others can be added by several methods.