The most common, high-volume, commercial printing technology is Offset Lithography. Offset lithography is a commonly used printing technique in which the inked image is transferred (or “offset”) from a plate to a rubber blanket, then to the printing surface.
This method of printing is best suited for larger quantities of printed pages, such as: letterheads, business cards, leaflets etc. It can be quite costly to set up, however unit cost decreases rapidly as the quantity increases.
All printed colour images are made up of four colours: Cyan (C) Magenta (M) Yellow(Y) and the key colour – Black(K). At the print facility all printed designs are separated into these 4 individual CMYK colours and exposed just like a photograph onto photosensitive aluminium sheets, known as ‘Plates’.
Each colour has its own plate, which is then loaded onto the printing press. This image is then transferred (or offset) onto a rubber blanket and then onto the printing surface – be it paper, card or plastics. The process relies on the repulsion of oil and water; the image to be printed gets ink from rollers, while the non-printed area attracts a film of water, so it remains ink-free.