I made these to learn just how fine a feature my printer can resolve at different settings. One pin has raised bars and pins, the other has voids. Print them out to see how small you can go with things.
There are a 10mm void and pin on the left plus a set of pins or voids that are 5, 4, 3, 2, and 1mm. There are another set of 5,4,3,2,1 voids on the bottom.
The center has a square and a bar at 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, and 0.1 mm with another set running down the right side.
Interestingly my printer generally stops at 0.6mm but does slightly better with lines running on the X axis and with voids rather than bars.
Labels were added but they may or may not print - depends on your resolution.