I needed a project for a Makerspace booth at an even. What I came up with was a simple-to- design ring printed flat and heated with a heat gun to bend it around a ¾" dowel to shape it for your finger. These work great, print in only a few minutes, and even better, they're easy to design. 

In fact it wouldn't take much to design a new ring. You could do it in Tinkercad, even! Just make a cube that's 50mm x 5mm x 1mm (or import the blank ring included) and design scribble of whatever you want on top of it, make it 2mm thick, et voila.