A poster stamp is physically similar to a postage stamp, but it is without a face value or denomination. Poster stamps were created to commemorate and promote products, events, or ideas. The first poster stamps were printed in Europe in the mid-nineteenth century, and their popularity quickly spread. The printing and collecting of these stamps peaked in the years before World War I. During the war, both sides used poster stamps in their propaganda campaigns. The popularity of poster stamps started to decline after the World War I, and by the end of World War II, interest in them all but disappeared. Radio advertising was replacing print mediums. Collecting poster stamps has experienced a minor resurgence since the end of the twentieth century.

The Exposition of Chemical Industries (now called The Chem Show) was first put on in 1915. Annual to start, the show is now biennial. It serves to bring together manufacturers and suppliers with people who work in the chemical process industry.