There are three sizes of inside parts empty, half and full.

Print settings.

• 0.4mm nozzle.
• Top and bottom layers, zero.
• Infill, Honeycomb, 30%.
• Perimeter, one.

If you use a 0.25mm nozzle you will get even smaller hexagons.

And for better print I would recommend to set the only retract when crossing perimeters setting to FALSE (in PrusaSlicer), Print Settings/Infill/Only retract when crossing perimeters.

NOTE: you might need glue.