Cornice boards are inexpensive and easy-to-make window treatments for your home. A cornice board is simply a four-sided wooden box. There is no bottom, and the wall forms the back of the box. Think of a cornice board as a wooden valance with a top.
Cornice boards can be upholstered with fabric, painted, or, most easily, covered with a wallpaper border. With just a few basic carpentry tools, you can build your own custom-made cornice boards in just one day.