An easy-to print sorting cup, that easily stacks when put away, while using table space efficiently when in use.

A fast print, useful when you quickly need a container for sorting, or just for using up those last windings of filament on a spool.

A very smooth design, to provide good bed adhesion as well as fast printing.

Walls are somewhat curved (part of a parabola, actually), both for stacking and to give the cup rigidity, so it does not deform and spill its contents when lifted (experiments show that a flat single wall cup will do just that!).

Print in vase mode with 2 bottom layers, a light colour, and with PETG for maximal durability. The nozzle size decides the rigidity: 0.4 - a rather flexible cup, good for puzzle pieces - 0.6 (my favourite) an allround cup that is even watertight - 0.8 - a very sturdy cup. 

This model ought to print well on any printer - even my old Chinese Prusa clone made from plywood prints it just fine.

Care has been taken to both minimise material use and maximise functionality, such as stackability, close nesting when deployed on a surface, rigidity through design rather than thickness, minimal material use and fast printing. With a 0.4 nozzle, the cup uses only 8 g of material, and prints in 53 minutes. With a 0.6 nozzle, the print time is 34 minutes, but 11 g of material is needed.

This model was originally prompted by trying to print these for sorting puzzle pieces:

https://www.printables.com/model/74649-interlocking-sorting-cups-hex-shape-version-2

I found that that cup were too small, too deep, had an interlocking mechanism that had me accidentally throwing puzzle pieces all over, and that printing a useful number of them would require a full spool of filament and days of printing. So instead of that over-engineered Fusion 360 approach, I made a lightweight design where simplicity was the goal.