- 1). Measure the width of the window. Start the tape measure at the outside edge of the window trim, and measure across to the opposite outside edge of the trim on the other side of the window.
- 2). Measure and cut a piece of MDF board to match the width of the window, 12 inches tall.
- 3). Measure and cut two pieces of MDF to measure 6-by-12 inches.
- 4). Nail the two smaller pieces perpendicular to the longer MDF board. Each one should be attached at the back on either side of the longer board. You should result in a three-sided "box."
- 5). Nail trim and molding to the top and bottom of all three sides.
- 6). Fill any holes and seams with wood putty. Sand the putty until smooth and flush.
- 7). Paint the valance a desired color.
- 8). Nail the valance directly into the window trim on the sides. The valance can also be hung using "L" brackets if there is no trim. These are screwed into the wall using the provided screws, and screwed into the new valance. Install one on either side of the window, and valance.
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