Made modifications to The perfect coaster AKA 'Perfster'
by magonegro http://www.thingiverse.com/thing:976069 . After printing the original I wanted some changes including more drainage so i raised the overall height and added square corners for water reservoirs. I also removed approximately half of the interior ridges. Many thanks to magonegro for the original design. Tell me what you think.

Coaster is square photo was taken at an angle

Printed with raft to keep the corners from peeling up and make it easier to remove from print bed. Hot glue some felt on the bottom after you remove the raft to keep it from sliding around on your desk.

Update: i hate rafts and now prefer hairspray on glass bed.