Tired of printing calibration boxes to test your axis only to throw them away?
Try these crosses. They render quickly and they're easily measured to determine where you're off.

These Crosses are great test for all of your axis.
When your test are complete there are always people that want them.
Besides, What better item is there in finding your way? ;)

C Cross Small= 35mm x 55mm x 5mm
C Cross= 70mm x 110mm x 5mm