This is a simple spring clamp.  They work great for light pressure glue-ups.  I made these specifically for gluing vinyl flooring in non flooring applications (eg guard wall caps) but they work good for all sorts of things, especially where you need 30+ clamps (even 2" C clamps get very heavy).  I wouldn't print them in PLA as you want the material to flex a bit.  I made mine out of ABS and PETG.  Vary the amount of infill and walls to adjust how strong the spring force will be.  In PETG I found 3 walls + alternate extra wall with around 35% cubic infill to work well for my application.  I would recommend starting there and adjust after testing.  None of the ABS clamps have failed yet but they do show signs of plastic fatigue on the inside corners so I would recommend to use PETG.  Included is the FreeCAD file to edit away to your heart's content.