This foot is often referred to as the “uneven foot”, owing to the different thicknesses of the two halves the sole. It is ideal for creating narrow-to-medium piping, as well as for sewing unevenly thick fabric layers, attaching thick tape, ribbon, cords, or hook-and-eye tape.
The right side of of the sole is higher than the left side, allowing it to ride easily over the fabric layers as you sew. TIP: when sewing on tape, the tape should lie under the right side of the foot flush with the edge of the thicker left side. This will allow the needle to catch the edge of the tape.