GARMENT CONSTRUCTION TIP To Keep Facings from Peeping Out, Understitch the Seam Allowance
Understitching ensures that a facing won't roll to the outside of your garment. Here's what to do:
Clip and trim the seam allowances as necessary and press them toward the facing. Place the facing right side up under the foot of your sewing machine, allowing the rest of the garment to fall to the left. Sew the facing to the seam allowances using a straight stitch and sewing close to the seam. Reposition the facing as you sew so that it lies flat.
-- Sarah Veblen
Adapted from "Facings Made Easy," Threads magazine, August/September 2003 (#108); photo: Scott Phillips.