This saddle t-square allows you to run lines parallel with an edge or perpendicular to it. It wraps around corners so you continue a line down an edge. The diamond shaped wholes keep your pencil centered to the line you're marking and means they will print easily. Holes for as fine as 1/16th of an inch.

It prints without supports standing on end. Requires good bed adhesion.

A brim is recommended. thin layer lines help with accuracy and clear numbers and markings.

Metric Version found here:

https://www.printables.com/model/1382239-saddle-ruler-square-with-metric-marking-holes-for