These phone cases were printed in Prusa I3, with a 0.3mm nozzle (brought from mixshop.com). NO SUPPORT NEEDED! EASY TO PRINT.
All components fits nicely without any need of polish. Remember to set a higher temperature for first layer to prevent the edges from curling and maybe add some brims. Pins have to be glued on, instant glue works well for me, and it never comes off.