Hopefully that idea will be practical -- I reckon the main thing would be to locate your front hairline point, and obviously, you instantly have your rear end-point as the thing is plastic and will not stretch or move. Another little trick might be to apply a little tape just at the front --a small little strip -- and that will help prevent the thing from inadvertently slipping back a bit ---you`d be surprised how even half and inch `out` when positioning a system can make the whole thing look `odd`. Hopefully it will be a practical and easy aid for people to mark out the area to be shaved --- let me know how it goes mrjoejohn, and anyone else who tries it out -- I`ve never done it myself but it just occurred to me this morning for some reason -- hope it`s a help anyway. Paul.