How to Line Corners of Lined Curtain Panels

Pre-wash curtain panel fabric if it is washable. Pre-washing removes the sizing, which is a chemical coating on the fabric, and also shrinks the fabric slightly; when you wash the curtains in the future, they won't shrink. Follow guidelines on the fabric manufacturer's label, though, because many upholstery fabrics are not washable.

Cut the curtain panel fabric and liner fabric to size.

Fold a 2-inch hem in the bottom of the curtain panel. Iron the hem, and sew it using a straight stitch on a sewing machine. If you prefer, hand-hem the curtain bottom. Make a similar hem in the lining, but make it a 3-inch hem rather than a 2-inch hem. The measurement ensures that the liner won't protrude from under the curtain.

Lay the two fabric panels with their right sides together, and pin them in place. The "right sides" will face the room's interior when the curtains are hung. Sew all three raw edges -- top and sides -- together. Snip a 1/4-inch cut in the corners of the curtains, but do not cut through the seams. The cuts allow the corners to lay flat.

Iron the seams so they lay open, including the corners. Turn the fabric right side out. Push a paintbrush or the eraser end of a pencil into the corners to push the fabric out and make a neat, crisp edge. Iron the panel, taking extra care when working on the corners.