Tuelip Square Medium Density Fibreboard Tea Coaster Coffee Doodle Printed Tea Coaster Set Of 6. A good quality coaster is beneficial in multiple ways. It enhances the dignity of mugs on one hand and protects the table from stains on the other. Select the coaster that looks best with your mugs or cups. Multicolor Color, Square Shaped,Material (MDF) Medium Density Fibreboard.