Determine the number of box pleats you want across the valance’s length. Keep in mind that the button-back corners require extra space next to the box pleat so placing one box pleat directly next to another does not work. A gap between each underfold that is at least triple the width of a pleat face allows you to fold back the pleat face and button it down before reaching the next pleat face.
Creating a box pleat uses the same techniques as constructing a box pleat for many kilts and women’s skirts. Use straight pins to hold down the pleat and sew along only one edge. A hot iron creases the pleats in place. Place a thin towel over the pleats before ironing if the material does not withstand hot temperatures. A finished box pleat is a gap in the material that exposes a strip of the same material located behind the face pleats.
Buttoning back the face pleats exposes the back layer material between the underfolds. Lay the valance flat, invert one face pleat and tack it down with a straight pin. You can either pull the face pleat back so the material is taut or tack it down so the material drapes slightly. Pinning down each face pleat along the valance before sewing them down gives you the opportunity to ensure the button-back corners are even from one to the next.
Place a button over the pinned face pleat and sew the button through the inverted face pleat to the underlying section. This technique creates a permanently buttoned-back box pleat. Sew a button hole into each inverted face pleat’s corner and attach a button to the fabric directly underneath for a box-pleat valance with optional button-back corners. Large decorative fabric buttons that complement the valance color draws attention to the opened pleat.