The growth of digital printing technology has brought technical advancements, more options, and exciting new features to today’s commercial printing. Offset lithography is the most common high volume commercial printing technology. In offset printing, the print image is burned onto a plate and then offset from the plate to a rubber blanket and then to the printing surface.

The lithographic process is based on the repulsion of oil and water. The image to be printed gets ink from ink rollers, while the non-printing area attracts a film of water, keeping the new printing areas ink-free. Digital printing eliminates many of the mechanical steps required for conventional printing, including making films and color proofs, manually stripping the pieces together and making plates.

The advantages of digital printing include shorter turnaround. Every print is the same with more accurate counts. less waste and fewer variations, due to not having to balance ink and water during press run. It also offers cheaper low volume printing. Offset’s advantages include high image quality and works on a wide range of printing surfaces including paper, wood, cloth, metal, leather, rough paper, and plastic. It also has quality and cost-effectiveness in high volume jobs.

Last week at Total Print in London, Heidelberg demonstrated how an Anicolor Speedmaster could be used for short runs with costs and times that compared with digital printing. The growth in demand for print in quantities is below 500 and offset typically generates a waste of the first 200 or 300 sheets.

Runs as low as 200 could be viable for litho printing because of the Anicolor inking unit and the Prinect digital workflow. The cost of ink gives litho an advantage for longer runs. Heidelberg is the largest supplier of equipment for offset litho printing, still the established method for most of the print industry. They support Job Definition Format (JDF), a set of standards to define a print product and associated workflow.

The Suprasetter S2 Computer to Plate system can produce up to 17 B3 plates an hour and a change of plates every quarter of an hour is necessary for four colors. The Anicolor inking saves 40% of the cost. According to Heidelberg, the Prinect Digital Print Manager could also be used with digital equipment from Canon, Hewlett Packard, Kodak, and Xerox. The new JetPress 720 could compete with litho for runs up to 2000 according to a display at Total Print.

Grahame King was a distinguished presence in the Australian art world for more than seven decades and he died recently as the age of 93. In the 1930s, he helped pioneer the new art of chromo-photolithography that transformed developments in color advertising in the print industry.

King was born in Melbourne, Australia and studied at the Working Men’s College and at the old National Gallery Art School before enlisting in the army. He took classes at the George Bell School and exhibited four paintings. After a stint in the army, he moved to London and stayed there for three years, painting and touring Europe. King returned to Melbourne in 1951 and drew upon earlier experiences which gave him an opportunity to operate a lithography press at the Working Men’s College.

King began experimenting with the medium that would establish him as a major practitioner in the field. He created lithographs over many years that have been seen in private and public galleries. He taught the art of lithography to several generations of students and he dedicated himself to pushing the art of printmaking. In the early 1980s, King was appointed a founding artist-member of the new Australian Print Workshop and served on its committee for almost ten years.

This process is aided by the use of computers. Alignment of the printing plates as the color portion of the image is applied that is being printed, is known as registration. The image will look like it is out of focus and the color will be wrong if the plates do not line up perfectly. A video image via a computer is taken of the registration marks placed on the press sheet. Each plate has its own mark. The computer reads each mark and adjusts to the position of each plate to achieve perfect alignment. This occurs while the press is running at full speed many times per second.

The process that features the way ink mixes together and is linked to plate registration is called color control. Ink is adjusted by a control panel. A master is created by having plates scanned and the data transferred to micro cassette. This allows the release of ink to be directed with pre-set values.

The printed product is completed in a process called bindery. Massive roles of now-printed paper are out and assembled so the pages are in correct order. Pages are bound by staples or glue.

Ink is distributed by a series of rollers. The press plates are dampened by water rollers and then ink rollers which distribute ink from a fountain onto the plates. The image area of the plate picks up ink from ink rollers. Water rollers keep ink off the non-image areas of the plate. Each plate transfers its image to a rubber blanket that transfers image to paper. The plate does not touch the paper and this entire process occurs at very high speeds.

The paper is left slightly wet by the ink and water applied and any smudging is avoided by having paper pass through an oven which runs at 350 to 450 degrees Fahrenheit. After the paper leaves the oven, it is run through a series of large metal rollers with refrigerated water running through them. This causes the paper to cool instantly and it sets the ink into the paper. This is done so the ink does not come off on the fingers.