A gauge printed at 0.3 layer height. Allowed me to instantly see whether the holes in the models I am drawing, would actually be the size I needed when printed in PLA. On the reverse are hexagon cutouts to test whether a nut would easily fit in a certain size. The number markings were difficult to see; filled with black paint would be the best way of making them stand out. May be of use to someone.I printed this with 0.3mm layers as that's what I generally use most.