I created a LEGO ruler based on the original design back in 2009 by LEGO themself. I added different high levels to be able to see the plate and brick height a little better. Printed with the default 0.2 mm PLA setting from prusament.
Add some multi color layers for even better contrast.
v2 update. Removed the MH letters and added a hole for hanging the ruler.
The author remixed this model.