The art of collecting beer coasters (or “beer mats” as they are called in Great Britain) is referred to as tegestology among its more sophisticated aficionados. But despite the fancy Latin name, paper-pulp beer coasters were patented in 1892 by Robert Smith of Dresden, Germany, for a very simple reason—to absorb the condensation and overflowing foam that tends to spill over the rim of a freshly poured glass of suds. People collect them now, but as with many pieces of paper ephemera, they were meant to be thrown away.

Made of thick paper pulp, these inexpensive square or round cards were sometimes used in warm climates to cover open glasses, thus protecting the precious brew inside from flying insects. But regardless of their placement, beer coasters were attractive to brewers primarily because they were cheap, making them a great vehicle to advertise products. In fact, the medium was so economical, breweries could afford to produce coasters for special events, or series of coasters with, for example, different messages or jokes on each.

One U.S. brewer who did a particularly good job with the series coaster was Piel’s of Brooklyn, New York. Its set of coasters from the 1940s showed a different cartoon character holding up a glass of beer (which was identified by a small arrow and the word “Piel’s”), stating “I don’t mind the grind,” with the beer being his reward. Characters included an organ grinder (of course), bike racer, and even a truck driver, which is an image that would probably not be approved today. A set of Piel’s coasters in the 1950s featured the short conversations of Bert and Harry, who were voiced in TV and radio ads by legendary comedians Bob Elliott and Ray Goulding...