Drink Coasters, coaster, beverage coaster, or beer mat, is an article used to rest beverages upon.
Pubs and hotels usually have beer mats spread out across the tables and are often branded with trademarks or alcohol advertising. In 1880, the first beer mats made of cardboard were introduced by the German printing company, Friedrich Horn.
Some coasters are collectible items, and to an avid collector, the variety collected will be many. But, here’s one I didn’t know. There is a collective noun for coaster boasters. Tegestology is a Latin term defined as the practice of collecting beer mats or coasters, therefore, collectors are known as tegestologists