The diagram illustrates a method called ‘lithography’, a process used for printing newspapers. After the image is transferred onto a press plate, it goes through several rollers before being successfully printed onto paper.
First, the plate is passed through dampening rollers, which provide a mixture of water and chemicals. This is to dampen the non-image areas. Secondly, the plate passes through a set of ink rollers, in order for the ink to stick to the image area. Thirdly, the plate then goes through the blanket cylinder. This is to squeeze out the water and the inked image area is picked up. Finally, the plate passes through the impression cylinder. The paper then runs between the impression cylinder and blanket cylinder, pressing the image onto the paper. After that, the paper is dried with hot and cold air and put on the delivery pile.
Overall, the diagram shows that there are four sets of rollers used, before the image is transferred onto paper.