How Do You Make A Window Cornice Box?
Top treatments for windows are based on three styles: a structured cornice, the softer valance or draped swags and scarves. These instructions are for making a rigid structure, the cornice board, most often made of plywood and usually mounted above the window frame. A cornice is planned as part of the overall window treatment—after a roller shade or drapes are already in place. It’s most common use is to cover drapery hardware and rigging. Cornices can be painted or padded and covered with fabric. These instructions presume you are going to cover your cornice board with fabric and install it onto the window wall on an outside mount. Measure the drapery rod—or the window frame if topping a roll-up shade—and, as a general rule, add an additional 3 to 4 inches on each side to allow for the fullness of the drape. The height of the valance has two schools of thought: either 1/4 the total of the window height, or a height of 1/8 the depth of the curtain. If you make a cardboard templat
