this is a simple picture hook to complement the Hillman picture hanger, i printed this in eryone marble pla just because that what was loaded on my printer at the time. but any white filament will do. 50% infill more than enough, use a brim to ensure good adhesive to the build plate because it is very small. yeah! that's it nothing special. use a small nail to attach the hook to the picture frame, i use double sided tape just for demonstration porpoise only.