A series of basic angle gauges for measuring or setting inside and outside angles. These were made for a specific project to set my cold cut saw at certain angles (see photo) and I guess I will just keep adding files every time I need a different angle!

They're also exactly 20mm high so they can used as a height gauge as well.  If you wanted to save filament you could always make them shorter in your slicer as well. 

PLA/PETG or any similarly stiff filament will work fine, I've printed with 5 walls and 5 top/bottom layers with 30% infill to ensure it's strong enough that it won't flex.  This is probably overkill and I suspect standard settings would also work fine.