PLA with a .4mm nozzle and .1mm layer height. No supports. The HBS-730 clip is 1mm thick and stronger than needed. The HBS-700 clip is .8mm thick for faster printing at .8mm wall thickness and seems strong enough. This thickness prints quicker due to fewer passes. I'm printing on the Monoprice Select Mini which gives excellent quality at .1mm layer height and 50mm sec speed. FreeCAD files included.