"Seas of the World". This is a set of four 4"x4" coasters depicting different seas of the world. They are created from 1/4" MDF with resin art. After the resin art is cured they receive a final clear coat of resin which locks in the colors and gives a water and stain resistant coating. The back sides are sealed with shellac and have cork to protect your furniture. Each one has our logo burned into the cork. No two are identical.