These are clips which work with 1 inch OD (3/4" ID usually) PVC pipe to either hold fabric/cloth, hang items, or to act as a "stopper". They are very strong when printed at a high infill percentage and I added helper nubs to each part to facilitate easier removal. The main clip design was heavily influenced from the "U Clip For Greenhouses" (http://www.thingiverse.com/thing:26400) which I re-created in my own image to make the hangers I required for my project.
The clips included are:
PVCclip - Main U Clip, clip size can be adjusted in all dimensions
PVCclipDouble - Pipe joiner
PVCclipHangr - Item hanger
PVCclipHookHoldr - Hanger for larger items
PVCclipHangrLock - Item/cloth hanger with lock
None of these parts require support, I utilized rafts in order to have the bottoms perfectly uniform. Printed in ABS with 3 shell layers, 7 top and bottom layers. My infill for these parts was 90% (for strength) and layer height 0.12mm, feel free to change them to your desired amounts.