The Chess on Stamp Study Unit (COSSU) is an active group of chess stamp collectors and enthusiasts. We are a not-for-profit, official affiliate of both the American Philatelic Society and the American Topical Association .
This site includes our latest auctions, the items in our Society Sales Service, checklists, as well as articles about collecting chess-on-stamps.
We have also added a slide show of rare and unusual chess stamp items. We hope that you enjoy it. In addition to rare chess stamps, the exhibit contains many of the earliest postmarks that feature chess.