Summary Small shelf mounts to wall with two #8 pan head screws. Instructions Print upside down on the shelf side. I printed mine at: 20% infill 3 shells layer height of .2 bottom/top thickness .6 The scad file contains an option to printout just the hole area as a sample if you like to test your prints for printer calibration before printing the full model. If your printer is calibrated, the holes should accept standard #8 countersunk screws.