how it works

Offset printing is a commonly used printing technique where an inked image is transferred (or “offset”) from a plate to a rubber blanket, then to the substrate. The offset process is a lithographic process. Lithography is a process based on the repulsion of oil and water. An image that is offset printed is separated into its fundamental colours. A printed brochure for example would be broken down into the primary printing colours; cyan, magenta, yellow and black (CMYK). Thanks to computers this process has become easier. The image is broken down into these four colours and four separate plates are made.

Printing the image

A printing plate is made up of areas that are receptive to grease and areas that are receptive to water.
The areas receptive to grease hold onto the ink while the other areas attract water and repel the ink.
Plates are then put on to a press. From the ink fountains, the press pulls in the ink and puts it onto the plate. The press applies great pressure to the plate and the ink imprints the image from the plate onto a rubber blanket. The image is then pressed onto the paper off the blanket to make a print.

This happens really fast and many impressions can be made from one set of plates. It is a very efficient process and lends itself very well to long runs over a long period of time.