Actualy, no problem at all. There are three distances (purple/red, orange, yellow). Opposite side track is measured in centimeters (0.4'', roughly). It's not problem to recreate it on the stick (if one wants to).

But I have another question about ruler: First "half" (purple/red, orange) is 12.2 cm; other "half" (yellow) is 12.7 cm. Is that difference supposed to be?
If not, what half's length should be?