Update: Printed a few test runs, and uploaded a new version. This version is smaller diameter, but stacks nicely and has the right heft from what I remember.

I'll upload a picture when I get a set printed. I'm going with 30 mm diameter, 0.3 layer height with 50% infill and they come out like I remember checkers "feeling" as a kid. It has a nice "click" when you slid them together.

Working on a set of checkers for my son. These are thinner and hopefully will stack. I made the underside ridges rounded so hopefully this will help with bridging.

This thing was made with Tinkercad. Edit it online https://tinkercad.com/things/4SkOLS948I5

Print 12 Red and 12 Black, and play some checkers!