Advanced Calibration Cube

This is an advanced calibration cube. It has a cutout inside which contains a pillar with 3 bridges going in different directions. So in addition to regular features of a calibration cube such as:
- dimensions test (20x20x20 mm)
- ghosting/ringing test on debossed letters

And here's the additional features:
- overhang printing ability test (up to 75 degrees)
- bridging test (about 10mm)
- retraction test (between main body and pillar)
- additional thin embossed letters inside debossed