Box Pleating
This is made by turning the first pleat to the left and the next to the
right. The same amount of material is required as for side pleating. If
the pleats are to be one-half inch deep, the box pleat will be one
inch across. Baste with silk thread at the top and bottom, and press on
the wrong side. A simple box pleating may be basted through the center
and the edges caught together.