Designed by a professional engineer in her spare time, this no-nonsense ruler/combination square allows you to quickly measure objects for lazy gridfinity-ification. This model focuses on practicality, minimal filament usage, and ease of manufacturing. A reinforcement in the center ensures the ruler is stays stiff and rigid even when printing with PETG (for you nerds out there, there's simply material concentrated mostly at peak bending stresses). 

One side measures in 42 mm increments for bases, and other side measures in 7 mm increments for height. 

This design shines in multi-material printing, and can easily be done manually. If done manually, simply pause the print and change filaments at the layer were the lettering begins, then finish the print.  In automatic systems, you can print without any purge. Efficiency!