I use to make drapes for people. I went to classes to learn how and the FIRST thing you do after measurement, is the hem. Yes that is what I said. (the hem should be double) You hem, then lay out the the hemmed panel and press the side hems in and sew. Then you lay out and measure from the bottom to the top and press the top banding over to your measure ment. Will hang perfectly straight when you put on rod.