OFFSET AND DIGITAL PRINTING

Offset printing is a technological improvement in lithographic printing. The offset process was invented in1798 by an Austrain printer, Alois Senefelder.

Lithography listerally means writing on stone and it is based on the principle that grease or oil and water do not mix. Working on a very porous stone, Senefelder sketched a design with a greasy substance that adhered to the stone. He then wet the stone's surface with a mixture of gum arabic and water. The mixture wet the blank (non-image) areas but was repelled by the greasy (imaged) areas.