The link is working for me.

That mat is cool. I bet a person could make something similar using wet sand for a working surface then put down some thin plastic and liberally applying latex paint ($5 a gallon in the oops area at Home Depot). I would just hate to buy one of those and then carve it up for a cavern floor, although that would make a really nice floor.

Pete
Democracy is two wolves and a rabbit voting on what is for lunch.

Liberty is a well armed rabbit contesting the vote!