Cookie cutter- Shut up and take my money

Median wall thickness is 0.6 mm (suitable for 0.3 mm nozzle). When using other nozzles, I recommend scaling proportionally. If the walls do not adhere near the corners, you can increase the flow value and try a better linear/pressure advance factor.

Parts can be combined in the slicer by setting coordinates. I make a grid with ultimaker cura, but many other slicers have similar functionality. For the "bot" part, the walls, top and bottim should be removed. Then you choose the desired pattern and infill size. The infill overlap is negative.

The scientists argue that on average people could be ingesting approximately 5 grams of plastic every week. Don't make things worse, you can calibrate the retraction beforehand and remove remaining after printing threads and burrs with a box cutter.