Knitting needles generally have a long shaft and taper at their end, but they are not nearly as sharp as sewing needles. Their purpose is two-fold. The long shaft holds the active (unsecured) stitches of the fabric, to prevent them from unravelling, whereas the tapered ends are used to form new stitches. Most commonly, a new stitch is formed by inserting the tapered end through an active stitch, catching a loop of fresh yarn and drawing it through the stitch; this secures the initial stitch and forms a new active stitch in its place. In specialized forms of knitting the needle may be passed between active stitches being held on another needle, or indeed between/through inactive stitches that have been knit previously.