Overcast stitch
Overcast stitch is one of several types of sewing stitches, this type being used on a raw, or unfinished, seam or edge. The purpose is to prevent unraveling of the fabric.[1]
Overcast stitches may be reversible, as when they are used to join together crochet block pieces of afghan blankets. There are several different kinds of overcast stitches. A straight overcast stitch is used for finishing edges in eyelets and cutwork fabric.[2] A blanket stitch, used to finish edges of wool blankets, is another common overcast stitch.
Embroidery
In embroidery, an overcast stitch is a raised line stitch used on even-weave fabrics. It is commonly used for outlining designs. There are two methods of creating an embroidered overcast stitch. In one method, a line is stitched to create padding, then another thread covers the padding stitches in small stitches at right angles to the padding stitches. The other method is called detached overcast stitching, and involves two alternating padding stitches that pick up the fabric, followed by overcast stitches that cover the padding stitches without picking up the fabric.[3]