Physicist Glass Tile Coaster Pessimist: The Glass Is Half Empty, Optimist: The Glass Is Half Full, Physicist: The Glass Is Full of Liquid and Air. Get this fun Ultra Geek design on shirts, stickers, and more! Product InformationLiven up any room or party with our fun, hip tile coasters, measuring 4.25" x 4.25" and 1/6-inch thick. Images are applied with a polyester resin that accepts dye as part of the coating. Four felt pads protect your furniture from scratches. Dishwasher safe. Not for use with abrasive cups and mugs. | 
