A poster is a temporary promotion of an idea, product, or event put up in a public space for mass consumption. Typically, posters include both textual and graphic elements, although a poster may be either wholly graphical or wholly text. Posters are designed to be both eye-catching and informative. Posters may be used for many purposes. They are a frequent tool of advertisers (particularly of events, musicians, and films), propagandists, protestors, and other groups trying to communicate a message. Posters are also used for reproductions of artwork, particularly famous works, and are generally low-cost compared to the original artwork. The modern poster, as we know it, however, dates back to the 1840s and 1850s when the printing industry perfected colour lithography and made mass production possible.