
A poster is a large piece of printed paper that has a message, usually with picture of something. Posters are made to be shown in public on a wall or other flat surfaces. They were the main form of public advertising before the web, and they are still used.
Posters are used for advertising, education, propaganda, and decoration. They may also be copies of famous works of art.
Chromolithography (color lithography) was invented by Engelmann & Son, who were granted a patent in 1837. After that, it was a matter of time before it reached full commercial development.
Because of its low production costs, over the 50 years after the American Civil War, millions of chromolithographs were printed and were sold for under $10. Louis Prang, a Bostonian, produced fine-art subjects, such as still lifes, landscapes, and classical subjects. Nevertheless, it was only after 1847 that the Jules Chéret posters showed their real potential.
Posters were used for war propaganda, to encourage young people to enlist in the army, and to sell government war bonds. From a strictly artistic view, the posters were unimaginative and far from the masterpieces of the late 19th century posters. The posters almost all came with a caption to bang the message home.