|The picture shows the principle of the offset printing procedure (level print)|
|The modern Offset Printing
is an advancement of the lithography fictitious in 1796 by Alois Senefelder (likewise a level print procedure). Besides, stone plates were used as printing forms by means of hand pressure. The paper supply as well as the decrease after the pressure occurred by hand. In the course of the years pliable metal plates were used instead of the stone plates as printing forms. Mostly was printed by zinc plates. In this connection the problem arose that could not be printed by the zinc plates on metal boards (hard on hard). To solve this problem, an elastic rubber cylinder was interposed. Through this the indirect level print came into being, or the indirect rubber pressure which was applied later in the offset's machines. Today the original lithography is used only in the artistic area. However, into English are "lithography" and "lithographic printing" still synonymous with offset printing. Today principally newspapers and advertisement posters are produced in the offset printing (level print), because the rollers offer only approx. 10 mms to 20 mms of open air space in the pressure machine.