Measure the length of the curtain. Measure the curtain band material so it is 5 to 6 inches longer than the curtain. Cut the curtain band into a strip of fabric 6 to 8 inches wide.
Hem the sides of the curtain band. Fold over each side of the band by ½ inch and iron it flat. Sew the sides with a straight stitch.
Iron the top and bottom hem of the curtain band. Fold over the fabric by 1 inch on the bottom and 3 to 4 inches on the top so the frayed edge is sandwiched inside the other material. Iron each side flat and sew it with a straight stitch. Leave an open channel at the top of the curtain band for the curtain rod.
Sew the curtain band to the side of the curtains. Line up the area for the curtain rod with the original curtains and pin it in place. Sew the curtain band to the curtains with a straight stitch.