Lithography (Litho).

Litho is method of printing at an industrial scale in which inks are transferred onto aluminum plates to make an impression.

All printed colour images are made up of primary colours: CYAN (blue), MAGENTA (red), YELLOW and the Key colour BLACK (CMYK). The design (artwork) is set-up on a computer and all the colours on the artwork are separated into CMYK and sent to the plate making facility.

The artwork, now split into 4 individual colours, are exposed just like a photograph onto photosensitive aluminum sheets, known as ‘plates’.

The plates are collected by the printer and inserted into the press by clipping onto a roller.

Each plate is coated with its corresponding colour by a smaller ink roller. The coloured image is rolled or ‘offset’ onto a cylinder (blanket), which makes an impression on paper being fed through the press.

As the paper moves through each set of rollers, the colours mix to create a full colour image on the page.

The pages are guillotined and collated. They are then taken to the finishing department for binding, punching, numbering etc.