Needed paint pallet ring. Thought to design one and- aha! Someone already did. Except I wanted it to have a hinge so it would travel easier without fear of breaking.

TADA!

Teamwork makes the dreamwork.

Thanks OG, made this super easy to tweak.

Note- measure finger and add 5mm. for instance, my thumb is definitely smaller than 3cm (30mm) so I printed one at 35mm (3.5cm) for the extra adjusting the X axis size. It was perfect! May need to tweak/make more till it fits snug. Also, took lighter under it for just a moment, held it closed so it would shut flush to itself. Cooled off to leave perfect fit.

I used triangle pattern to help resist the assumed shear. Raft to ensure small print works first time.