I made these at TechShop, an amazing place with several outposts in the US. It's a production shop with tools for metalworking, woodworking, industrial sewing, vinyl banner cutting, electronics and arduino, laser cutting and more: http://www.techshop.ws
Step 1: Glass coaster in laser
* I got a local glass shop to make me some 6" x 6" coasters with little non-skid circles on the bottom and created a 5" x 5" design in Adobe Illustrator.
* I decided to put the design on the underside of the coaster so it wouldn't get dirty when it was used, so I flopped the design so it was backwards and would be right-way-round from the top.
* I put the design on a flash drive, transferred it to the computer attached to the laser and opened the file.
* I adjusted the settings for glass, hit Print and started the laser.