A question I asked when these first came out: how hard would it be to print a faint graphic on one of these? I glued a metal whiteboard to a utility table for

A question I asked when these first came out: how hard would it be to print a faint graphic on one of these? I glued a metal whiteboard to a utility table for gaming; the 1" grid dots are pretty important for the games we play. If I could get a Bertha with pre-printed grid dots I'd be all over it. Alternatively, how opaque/translucent are these? If I drew grid dots directly onto the table surface and then placed Bertha over the top, how much would the dots show?