I made this when I was mounting a Hemera to my Ender 3 with a custom print head mount so I could easily measure print head and probe offsets.

Layer height .32.  Line width .2mm.  Lines are 2 wide, so all lines are .4mm wide total and spaced 10mm apart.

There are 2 models, 1 with X grid and 1 with an XY (square) grid.