Go look in your desk drawer, got a bottle of whiteout in there? Cheap and works wonders. I learned this one when I was 17 on the rifle range in boot camp. My shooting coach put some on the rear sight index marks on my rifle and it made them really stand out. It also lasted. You aren't looking for something to withstand the heat of reentry on a spacecraft so keep it simple easy and cheap. Go with the whiteout.
BTW, white catches the eye a lot better than black. Dan
