A two-piece coaster. Has an outer "frame" and inner "core". The core is solid - I used the slicer to print it as a hex mesh. To do this, use the following settings:
I think that concentric top and bottom solid infill looks nice for the frame. Pictured printed in Polymaker's thermochromic (color changing with temperature) PLA for the core.
The author remixed this model.
Redesigned to allow printing the inner core using different infill patterns