FlowShow

Simple 3D print test of extrusion consistency over 20mm x 20mm. I assume a .4mm nozzle (you could easily scale for others) so your slicer should only make 1 layer by 1 perimeter of the simple zigzag pattern.

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/j0PLDeQISfw