Inspired by the remix, I put together this parametric ring in Fusion that lays flat for easy printing. It allows you to change the inner diameter (size) along with the thickness, setting angle, and setting height in the Fusion360 parameters (all in the favorites with notes). Throw a "gem" on it and it's substitute bling! I used this one: https://www.thingiverse.com/thing:19137 (clear glitter filament, 1 outer layer, 10% infill for maximum clarity)

Might try this in TPU for a flexible version someday.