I keep one of those water-brush pens handy and TRY to remember to remove blue lines ASAP after quilting over them. I need to take frequent breaks to stretch my back and move around anyway, so that's a little "chore" I can do during those breaks; usually without even removing the quilt from the machine. Otherwise I'm so afraid I'm going to forget and iron the marks in while I'm doing the binding or something. I haven't done it yet, but I'm sure it's only a matter of time...