This, although I use a Rotring Rapid Pro mechanical pencil. I only use that because it's less messy and much heavier than a normal pencil so it's easier to writ

This, although I use a Rotring Rapid Pro mechanical pencil. I only use that because it's less messy and much heavier than a normal pencil so it's easier to write with, plus the end doesn't break off in your pocket. I have a pen for signing as well but it's got a Fisher space pen refill in it they flow reliably meaning no grinding on a sheet of paper to get ink out. Plus it works upside down and all sorts which is handy for signing pizza cheques on my doorstep :)