
When you learn how to cover a cornice board, you will discover an easy way to create an elegant window treatment for your home. Cornice boards have made a comeback due to their clean lines and design versatility - they can be modern, traditional, or anything in between. Making your own custom cornice boards will allow you to play with different shapes, fabrics, and trims for a truly one-of-a-kind look that will have friends and family amazed.
Where to Start
The first step in learning how to cover a cornice board is to get accurate measurements of your windows. It is completely up to you how tall and wide to make your cornice. In general, you can extend the cornice four to eight inches out on either side of the window. Use a wider size if you will be placing draperies under the cornice board.
The typical depth or height for a cornice topper can range from about twelve to twenty inches. If you want your windows to look taller, try eighteen inch cornices which are mounted so they extend the height of the window. The return of the cornice board is how far it sticks out from the wall. This is usually around three to six inches with deeper returns used when there are draperies or hardware underneath.
Building a Custom Cornice Board
A cornice is basically a U-shaped box with three sides. This consists of a front decorative panel and two end pieces that form the returns and connect the cornice to the wall. The top can left open or filled in with a piece of wood or foam that can serve as a dust protector or shelf.
You will also need to decide on the best materials for your window treatment. Cornice boards can be made from wood, MDF (medium-density fiberboard), plywood, Styrofoam, or foam core. The wood and wood-like materials will allow you create custom shapes if you know how to use a jigsaw (or know someone who does). The lighter foam materials can also be shaped, but these may limit your design to more simple silhouettes. Companies like Create It Décor specialize in kits to make lightweight do-it-yourself cornices.
Using your window measurements as a guide, decide on the dimensions of your cornice board. Keep in mind that your local hardware store can usually trim wood pieces to match the measurements you give them. If you choose to make a foam cornice, cut it to size with an electric carving knife, heated serrated blade, or box cutter. Assemble your pieces using wood glue and nails for a wooden cornice, or assemble a foam cornice using basic white glue along with toothpicks or floral picks.

Covering a Cornice Board
Knowing how to cover a cornice board is the next step. First, choose a designer fabric which appeals to you from your neighborhood fabric store or shop an online retailer like Fabric.com. For a long cornice board, think about using your fabric "railroaded" so that there are no seams needed. You can also find large pieces of attractive fabric in bedding sets or shower curtains. Some people want more texture and select a funky material like bamboo placemats for their cornice.
Start covering your cornice board by applying a layer of batting for a truly upholstered look. This cushy covering should be wrapped around the inside edges of the cornice and can be attached using a staple gun along with glue.
Applying the fabric to a cornice board is often compared to wrapping a present with paper. You will want to make clean edges by keeping the fabric taut and folding in an envelope fashion around the back of the cornice. Once again using a staple gun, you should secure the fabric with an ample amount of fasteners. When making a foam cornice board use glue or pins to attach your fabric of choice. For a dressy look, you can add decorative trim such as beads, fringe, cording, or tassels with hot glue.
Wooden cornice boards are usually attached to the wall using L-brackets which attach to the top or sides of the cornice. Make sure that the cornice is securely fastened to the wall using screws or anchors. Foam cornice boards are lightweight and can be mounted on the wall using nails or Velcro.