The beading presser foot is also called the sequin foot or pearl foot. The beading foot is used as its name implies, to sew beads or pearl strands onto garments or other projects. Generally invisible thread (also called monofilament thread) is used for the upper thread spool and thread to match the fabric is used in the bobbin.
The stitch used is an heirloom appliqué stitch or overcast stitch also called the zigzag stitch on some machines. The presser foot generally comes in two sizes, one with a small groove size for beads or pearls less than 2 mm and a foot with a larger groove for beads or pearls from 2.5-4.0 mm.
This presser foot is generally a clear foot with a groove under the foot in the center, although some manufacturers offer a metal foot, and generally these are the serger version of this foot. The clear presser foot makes it easy to see the beads as they are sewn to the fabric, and it helps to see that the needle is properly clearing the beads. This groove is where the bead is inserted. Stabilizer is also placed under the fabric before sewing begins.
Adding beads or pearl strands to a garment or project can add an elegant touch and is great for crafting and decorative embellishments. This foot is not one of the standard feet that comes with most sewing machines and is usually purchased as an accessory foot.
For a nice short video on how to use the beading presser foot, click here on the link to Fancycollective.com.