I could sense you were all waiting with baited breath so I hurried back... :lol: drum roll.... they're all exactly the same, Omnigrip, Olfa, Sew Easy, some strange brand I bought in France. No difference, so long as, like dunster said, you line the marks up right, ie in the centre of the line. :-D Thanks for starting this thread though, I'll stop stressing about how I measure now. :-D