Two jaws for an F-style clamp that fit on a paint mixing stick. The movable jaw has a cam lever to lock it in place. The movable jaw its own supports built in - you do not need to add any extra supports! The clearances are 0.5mm.
The clamping force is not very strong! Enough to lift just under a kilo. I use them for gluing small pieces of wood together and it is more than enough force for that. From the images you can see that it's strong enough to hold 5 books.
3D Printing Canada PLA
Rotate both pieces so the curve is facing up. The fixed jaw can be printed with a coarse layer height. The movable jaw should be 0.2mm or finer. No need to add supports, as they are built in.