The whip stitch, and its cousin the blanket stitch, is a form of hand sewing that helps in finishing edges.  It's a decorative but also very functional stitch.  It can be used on a single or double layer of fabric.  If used on the edge of two layers of fabric, it'll help bind those layers together.  You'll basically be crossing over from one layer to the next layer, so not only will you have a diagonal thread on each side, but also thread that will be along the top as well.  The whip stitch and blanket stitch, when done well, can add a finished look to your project and make it very beautiful.  We show you how to do both versions.