Mug and coaster in one. I don't know; I usually don't use a coaster anyway. Precarious? Prone to dripping water down the coaster when it's used, because the coaster surface is not absorbent?
https://diqn32j8nouaz.cloudfront.net...erless_mug.jpg
Previously:
https://www.homemadetools.net/forum/...286#post101209
https://www.homemadetools.net/forum/...3095#post98045
https://www.homemadetools.net/forum/...502#post122792
https://www.homemadetools.net/forum/...2625#post96734
