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Putting Pictures on Paper

Monday, 03 March 2014 | By Gerry Mulvaney


By Gerry Mulvaney, European Sales Manager, Landa Digital Printing

Putting Pictures on PaperWhen I was starting out in the industry, printing pictures was not putting a tick in a computer box to designate the screen ruling required. Back then it was a much more mechanical process and in the course of producing black and white or colour pictures, a group of very highly skilled people were involved. The camera operator’s job in a printer’s darkroom was highly sought after, not just because when the red light outside was lit, the boss could not enter and see what the operator was doing, (although that was when an operator could enjoy a coffee and read of his newspaper undisturbed!) but because the conversion of artwork to a printing plate was a well-rewarded skill.

The Process of Printing with Photographic Film

The camera operator’s job was to take a continuous tone photograph and expose it onto a piece of photographic film, under a vacuum, through a film screen made up of a series of holes, to create a half tone image. The film image used a series of dots to create the illusion of highlights and shadows, much in the same way that modern computer systems do today.

When the artwork was exposed through the camera and film screen, dots ranging from 10% through to 90% density created the picture tones. The exposure time controlled the dot sizes and a whole range of external influences, from the brightness of the lamps and the dust on the film screen, to the film processor chemistry all contributed to make the operator’s job harder. All done in the glow of a red safe light, because the films used would be fogged by normal room lights.

Of course black and white printing only needed one sheet of film, but to print colour, the camera operator needed to filter Cyan Magenta Yellow and Black from the picture and expose each of the colours using the same process of screening.

If the operator got the exposures correct, the films accurately positioned and the angles of each screen set properly (another hurdle to ensure that moiré patterns* did not appear in the final printed result) then there was every chance that the end result would now only need the press operator to do his job properly.

It was a wonder to my unskilled eye that pictures printed properly at all given the exacting process that was used to create them.

Printing Images the Hi-Tech Way

Gradually I started to see, during my career, technology arriving to simplify the process. Colour scanners used computers to calculate exposures and lasers imaged the dots. Apple Macs arrived and with them digital printing, all of which started to make the camera operators role redundant.

Now Landa’s Nanography® process will take the technology to another level. Printing at offset press speed and a B1 (41 in./1050 mm) format, every sheet will have colour pictures created fresh, pixel by pixel, using EFI expertise in the Digital Front End. The Landa press operator will have a very visible role on the production floor, but will no doubt still have time for that cup of coffee!

*Moiré pattern: an undesired interference pattern created by overlapping grids or lines.

Landa S10 - Printing Press