I’m going to have access to a 3D printer for a few days. I know two friends who’ve used them, but it’s only been for art and figurines, or professional purposes.
Are there any other cases you can think of where a custom-printed item is better than the myriad of mass-produced plastic items?


None at all. 3D prints are almost always worse than injection moulded plastic. Only if you need a very specific custom thing. Or it’s just convenient/fun to make your own.