When making a box pleat valance, it is important to keep the fabric and support in mind. A box pleat valance is a long piece of folded material. The fabric needs to fold well to maintain a square tailored look. The pleats work best with crisp cottons or linens as opposed to lightweight or bulky fabrics. Another factor to consider is how the finished box pleat valance will hang. A valance can be board mounted, but it is easier to use a rod support. A valance with an attached border has a neat finish and an instant sleeve to thread the fabric onto the rod. Here are the essentials to making your own.

Step 1

Measure the window's width and length. Add to the width, the amount the rod extends on each side. For 30 by 60 inch window with a standard 2-inch rod, take 30 inches and add 2 1/2 inches for the left side and 2 1/2 inches for the right side for a total width of 35 inches.

Step 2

Estimate the length of the valance from top to bottom. The finished valance covers 1/6 of the window. Divide the length of the window by six. Take the figure and add 1/2 inch for the seam at the top and 8 inches for the bottom hem.

Step 3

Calculate the fabric widths. The finished width of the valance is three times the width of the window, so multiply the window width times three. For instance, a 35-inch width requires 105 inches of fabric. Note that most fabric is 45 or 54 inches wide. It is necessary to cut multiple pieces. For example, at least two pieces of fabric are needed for 105 inches.

Step 4

Measure and mark the length. Start marking at the selvage, or the finished edge. Continue to make a dotted line down the center of the fabric. Complete the cut lines by connecting the dots. Repeat until all the required pieces are marked. Cut the fabric.

Step 5

Cut the fabric for a border. Make the border 5 inches in length by the same width as the valance.

Step 6

Join the fabric widths by placing the pieces wrong sides together. Pin the fabric then machine stitch a 1/2-inch seam from the raw edges.Conceal the raw edges by turning the fabric right sides together. Press then stitch a line 1/2-inch from the edge. Open and press the seams flat.

Step 7

Hem the sides of the curtain. Lay the fabric right side down. Fold the fabric over 1/2-inch and press. Fold and press again. Pin and stitch in place. Create a double bottom hem. Fold the hem under 1 inch and press. Turn it under 2 additional inches, press and stitch to close.

Step 8

Divide the fabric width into equal sections. Mark the end of each section with a pin. Bring the first pin to meet the second pin. Bring the third pin to meet the second pin. Pin both folds in place. Repeat the process until each section is pleated. Stitch across the width of the valance 1 inch from the edge to secure the pleats.

Step 9

Attach the border to the front of the balance. Place the border fabric on the body of the valance right sides together. Pin the border in place. Stitch 2 inches from the edge.

Step 10

Fold the border back over to the opposite side. Sew the border to the back of the valance. Flip the valance over so the wrong side is facing up. Pin in place, tucking the raw edges under as you go. Stitch in place.

Step 11

Hang the box pleat valance. Thread the valance on a rod from the border.