Messages were not permitted on the address side of the cards; after attempting various forms of explaining that regulation, the U. Post Office adopted the printed message that This side is for the address only (Staff, p. Other backs from this pioneer era of the American post card are known today as Souvenir Card and Mail Card. In this era, private citizens began to take black and white photographs and have them printed on paper with post card backs.
Much of the contents of these guidelines were excerpted with permission from the Beginners Guide to the Hobby of Postcard Collecting, The Capital of Texas Postcard Club."The best printed cards were produced done by the photogravure process.They are difficult to discern from real photos but usually don't have the glossy finish of photographs.Chrome postcards began to dominate the scene soon after the Union Oil Company placed them in its western service stations in 1939.Mike Roberts pioneered his WESCO cards soon after World War II.