To print these properly, it is important to set up PrusaSliser as follows: 0.2 mm layers 0.45 mm for all extrusion widths 3 perimeters 0% infill 0 solid layers top 10 solid layers bottom 30 mm/s for all non-travel speeds is recommended Add a material change at layer 8 to switch from PETG to TPU Print them one at a time to reduce blobs and stringing.