As items that were made for sale at low prices to the masses postcards, and their earlier incarnation, stereo view cards are an easy way to start collecting railroad memorabilia without breaking the bank. Whether the card has been mailed and postmarked or is unused there is always a market, some collectors prefer mailed cards because they are dated by a postmark and have a message that brings nostalgia, while others like the pristine look of unused cards. Cards were produced by the railroads themselves, as well as other manufacturers. Stereo view cards are two almost identical images side by side on a single card. The card was inserted in a stereo viewer which gives the illusion of a 3-d scene. In general, the most valuable cards are the oldest, produced by the railroads, with interesting artwork or images, and in good condition.