Over the years, we’ve received a number of requests for ruling in a wide range of widths, (anywhere from 4mm, to 9mm) and I’m guessing that a preference for a specific size of ruling is primarily related to the size of one’s handwriting.
While I prefer blank paper, (so I can write as big or as small as I want) I have no problems working with 7-8mm lined ruling. 9mm makes me feel like I’m back in grade school, and 4mm makes my eyes go buggy because all I see are lines.
Do you have a preference for a particular line width? Do you need this width for reasons other than the size of your handwriting?