I printed with PETG, 90% infill, .16mm layer, no support. Printed on the back - it's the biggest flat face. The threaded holes have a couple of perpendicular crossing wells inside, so if you want to affix with epoxy, there's someplace for the epoxy to make a mechanical grab in there (epoxy will only make a mechanical, not a chemical bond with PETG and with the stud). Suggest you affix these with an adhesive - they tend to back off if not. Be gentle: the screw thread follows the weak axis.