Following on from FifteenTwenty, I made a hairline/single stroke version of the font especially for CNC use. This is a slight misuse of the OpenType format, but if you’re plotting/CNCing/laser cutting, the filled paths of standard fonts don’t work so well. Single-line (or stroke) fonts used to be possible in PostScript — the version of Courier shipped with early Apple LaserWriter printers was composed of strokes, rather than filled paths — but have fallen out of favour. If you have a device with a defined tool width, it’s better to let the tool make the width of the mark/cut. Here’s the hairline font plotted with a 0.7 mm pen to illustrate what I mean:
This font is almost invisible on screen or on a regular printer, so I don’t recommend installing it unless you have specific CNC/plotting needs. Please note that the font will cause your device to follow the tool path of each letter twice.