Offset printing, is a method of printing (documents and images on various media playback), which consists of applying a generally oily ink on a metal plate, usually composed of an aluminum alloy.

He method of printing offset is one of them systems indirect of printing, since the substrate (usually paper) not has contact with the iron matrix to transfer the image. Ink goes the aluminum plate to the cylinder portacaucho or mantilla to then pass to the paper (or other substrate), pressing between the portacaucho cylinder and the cylinder pressure.