These are Infill Samples for teaching and showing for examples.
They are infill sample files for the following infill types:
Archimedean Chords
Concentric
Gyroid
Hilbert Curve
Octagram Spiral
The Infill Samples are named 15% and 30% infill sample files for the following infill types:
Archimedean Chords
Concentric
Gyroid
Hilbert Curve
Octagram Spiral
However you can print them at any infill percentage that you like.
There is also a blank sample that you can change the infill in the slicer of your choice. Or you can upload it to Tinkercad and add the infill name.
There are gcode files for PLA infill samples. And .3mf and .stl files that you change change the infill settings.
The gcode files are 15% and 30% infill samples printed in PLA.
The author hasn't provided the model origin yet.