Reservoir coaster set with holder

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 coa