Because it’s designed for straight-stitching, Patchwork foot #37, #37D is ideal for sewing 1/4” or 1/8” (approx. 3 or 6 mm) seam allowances.
In addition, Patchwork foot #37, #37D features three evenly spaced markings (1/4” apart) on its side that make the square insertion of pieces in patchworking easier. A narrow groove under the flat sole serves as a thread channel for smoother piecing.