Filework in progress on my Leatherman Wingman. I measured out 1/8" increments, marked with a Sharpie marker, then use a round diamond needle file to work each side edge of the blade spine, doing a couple notches on one side, the another spaced between those on the other side edge, and repeat. It does take a while.
I should put some tape on the blade edge since
I'm doing this freehand with the blade locked open, or I know I'm gonna
cut myself, lol... One image edited with Picasa's 'cross process', the
other with 'neon'.