I've used the room darkening material from Joann's to make liners for curtains in a lodge in Alaska. It worked wonderfully, but I agree with the previous post --- it's expensive stuff. It's not hard to work with, but be sure your measurements are accurate before you cut it. And also decide how you want to mount your quilt curtain. You'll see some light glow from around the curtain if the curtain/liner is not flush against the window. It wasn't a problem at the lodge, but it might bother you a little.