I have just cut a groove on the wrong side of a board, a board which I carefully set in position to route, a board that was marked as to face and back, and bottom. Apparently my eyes can no longer read a 0.5 mm mechanical pencil mark in the absence of blazing sunlight. What are your favorite marking tools? # 2 pencil? ball point? chalk? In my experience my #2's are always broken just when I need them, the chalk wears off and ball point ink can be hard to sand out. What's your experience? Anyone have a handy solution besides reading glasses which I already have?