This is a coaster that requires two 3d-printed parts and one piece of cork (or leather, or anything else).

The design consists of a base, and a snap ring. The ring captures a piece of cork or leather that serves as the main topside surface of the coaster. 

There are two sizes of ring insert: one for a 1mm thick piece of material, and one for a 3mm thick piece of material (for instance, Ikea's SUSIG desk pad is 3mm thick cork).

Steps:

1. Print out the Base and one Insert Ring
2. Use the outside of the ring to trace a cut line onto the cork or other material
3. Cut out the piece of material (Hint: cut inside the line a millimeter or two)
4. Insert the material into the base, and snap in the ring (Hint: the inner chamfer should be facing up!)
5. Enjoy your favorite beverage with a new coaster!