About this 3D model

How come most coasters are flat and made of something non-absorbent so they're only useful at times when you don't need a coaster? Try using one of those when there's some humidity on a summer day and your drink is cold, and you end up with a puddle spilling over the edge and defeating the point of having a coaster. Even the ones made of absorbent stone don't absorb enough. Cork ones do all right but tend to get pretty ratty and even smelly, and they're hard to find. I saw Stanistani's coaster idea and liked the concept of a coaster that had ridges for the moisture to seep into, but people said in reviews that the little bumps didn't do that good a job holding up the cup. So I decided to make an approach that would have a bit more rigidity at holding up a cup, but still have room for it to drain condensation. Plus concentric rings just look cool, stylistically speaking. I also made a holder that stores six of the coasters stacked since they don't otherwise have any way of keeping themselves in a tidy pile.