I just spent the last two days trying to get this zipper pocket sewn into a backpack. The fabric was stretchy so it kept ending up long than the zipper. Then my machine kept messing up and i kept having to tweek it here & there. Finally i get it working and i put the zipper facing the wrong way, not backward or anything, just its right handed now and i specifically wanted it left handed! Needless to say im not going to redo it over something like that it lookes fine ill just have to open it from the other way is all. Oh the joy of sewing!