I used these self-adhesive cork squares for the backs of the coasters and these 10 mm clear bumpers for the back of the holder (one in each corner).
A BambuStudio 3mf file is included with everything colored correctly. If you're using the STL files you'll need to color the logo parts yourself. The logo is split into parts and is oriented face down in the file.
The author marked this model as their own original creation.