About the product: The Yingge ceramics adopts fine natural pottery clay. The process is high-temperature kilning. The porous property that is liquid absorbing keeps the surface dry. The product receives SGS certification. How to clean: To clean the tinted or stained surface, it is strongly recommended to use the toothpaste on a toothbrush and move the toothbrush on the surface gently, then rinse the coaster with tap water. It is also doable to clean the coaster by dipping it entirely in tap water with baking soda for 1-2 hours and rinse it with tap water. Note: Please place the product on a hard surface carefully and tenderly to avoid damage arising from collision.