Hmmm, could be a problem. Made with a hardboard bottom for extra longevity, these coasters are a great means of upgrading home decor or adding character to any professional establishment. 

.: One size (3.5" x 3.5") (8.89cm × 8.89cm)
.: Hardboard bottom
.: Quantity: one coaster per order
.: Assembled in the USA from globally sourced parts