Late to join this discussion, I know, but for the record my favorite paper for drawing lettershapes on, prior to scanning is Clearprint:
http://www.clearprintpaper.com/media/vellums.html
They might have changed their numbering system since I last bought some, but I used to use the 1000HP with 10x10 grid. This has a tenth of an inch grid which to me is much more humane than working in millimeters. Also it is a vellum, which in Clearprint terms means the paper is made of cotton and stands up to a lot of erasing and ink pools. It is also see through for tracing purposes.