A selection of QSL cards, which are used by amateur radio buffs to confirm a two-way transmission between stations. In use since 1916, they form an endlessly fascinating spectrum of vernacular design. The selection above are from a box of a couple of hundred I bought a few years ago that http://www.besttramadolonlinestore.com just keeps yielding amazing type, illustrations, logos, insignias, scribbles and annotations. Archive sites abound online, also, a typically absorbing Wikipedia article on the history of the cards here.