Posters, in the form of placards and posted bills, have been used since earliest times, primarily for advertising and announcements. Purely textual posters have a long history: they advertised the plays of Shakespeare and made citizens aware of government proclamations for centuries. However, the great revolution in posters was the development of printing techniques that allowed for cheap mass production and printing, including notably the technique lithography which was invented in 1796 by the German Alois Senefelder. The invention of lithography was soon followed by chromolithography, which allowed for mass editions of posters illustrated in vibrant colours to be printed.