Create your own 3D printed coaster with this STL file, designed to be easily stackable.

It comes in 3 sizes: (It will fit cups up to of the inside diameter, not matter what shape) 

95 mm inside diameter 

105 mm inside diameter 

115 mm inside diameter

Recommendation: 

On the bottom there is room for up to 8 adhesive rubber feet (depending on the shape). They can be up to 10x2 mm round feet. (I use 8x1.5 mm) 

The coasters are easy to print, and requires no support. I recommend using a layer height lower than 0.2 mm. I use 0.15 mm.

I welcome your feedback and suggestions. Enjoy!