CafePress - Hippopotamus Art Tile Coaster - Tile Coaster, Drink Coaster, Small Trivet 100% Ceramic/Polyester Resin Square coaster measuring 4.25" x 4.25", 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