The evolution of our wide format technology
by Andy McCourt
Ever since Encad - now a Kodak company - introduced the Novajet in 1991, large format digital inkjet printing has experienced double-digit annual growth. Can sixteen years of hard driving continue, or will the brakes go on? Andy McCourt looks at how it happened, the state of the market today and what might be around the corner.
We are living through an historical change in the way mankind communicates, every bit as significant as the 4th millennium BC Summerians pressing cuneiform dies into clay tablets and then firing them, making the first recorded history.
From 1826 when Niépce made the first true photographic exposure, film and plate-based photography has lasted 180 years. Englishman Fox-Talbot enabled the half-tone reproduction process in the 1850s when he used Hessian sacking to break a photographic image up into little dots.
In fact, as the creator of the first book to include photographs (The Pencil of Nature), Fox Talbot had been frustrated at the slow production process and wanted to link the image capture technology to the mass reproduction capabilities of the printing press.
Realising that purchasers of The Pencil of Nature would not know what a photograph was, the publishers saw fit to include an introduction, stating: "The plates of the present work are impressed by the agency of Light alone, without any aid whatever from the artist's pencil. They are the sun-pictures themselves and not, as some persons have imagined, engravings in imitation."
Photography went on to become a boom industry and made many fortunes for those both in front of and behind lenses - and for the inventors and manufacturers of the equipment and consumables. Hollywood would never have happened without photography.
In the past few years we have seen a dramatic decline in photochemically-reproduced images in both the professional and consumer arenas. If the photographic reproduction methods born of Niépce, Daguerre and Fox-Talbot reach 200 years of use by humanity, it will have done well.
And the reason is - Digital Reproduction.
RIPPING UP THE PAST
Just as photography spawned the halftone printing process, enabling the 20th century to become the 'century of media' with billions of newspapers, magazines and books, the printing industry catalysed the demise of conventional photography.
Seeking a method of rasterising (making a bitmap out of vector graphics) fonts to speed up typesetting, the phototypesetting manufacturers of the 1970s developed the RIP - Raster Image Processor. The Monotype company soon discovered that images as well as type could be rasterised and then incorporated these into the same sheets of film separations for exposure
onto printing plates. Thus the 'imagesetter' was born; hot-metal and phototype would soon pass away into history.
But in the late 1980s, as the PC revolution really got going, people at the University of Utah, USA, realised that graphical data could be used to drive other devices: laser printers, dye sublimation printers - and large format colour plotters used in the CAD, GIS and Architectural/Engineering drawing markets.
The first large format device to be driven by a RIP for photographic-quality images was not an inkjet machine. It was the Xerox Versatec, an electrostatic 'giant copier: It enjoyed a few years of success along with a similar machine from Raster Graphics but as the droplet size of inkjet diminished and the quick fading dye inks became pigmented, companies such as Encad, HP, Calcomp, Epson, Roland DG, Mutoh, Mimaki came to dominate the short-run large format market with RIPs from firms such as Onyx, ColorGATE, Adobe, Shiraz and many others with special colour management applications in the proofing market
RESOLUTION RULES
For photographic quality you need two things - long-lasting / wide colour gamut inks and very fine resolution. People don't want to see halftone dots on their photographs, art reproductions and close-range signage!
The original 300dpi Novajet could not really do this -unless you viewed from a distance. The enabling technology again came from printing, in the guise of stochastic screening. It literally means random; scattered. Instead of neatly formed largish halftone dots clustered into 'rosette' patterns for litho printing, it became possible to print with tiny random dots so small the naked eye can not see them. The visual effect is of a 'continuous tone' image, which is what photography delivers.
Zooming into the 21" century, large format digital reproduction is a booming, dynamic market and is replacing many traditional reproduction methods such as photochemical, screenprinting, manual sign writing, offset art reproductions, chemical proofing and even product decoration with the new flatbed UV-curing machines.
The technology works, works well and is not expensive. The convergence of plotting, ripping and media coating technologies, coupled with advances in software, image capture/storage, computer hardware and inks has created the fastest growing sector of the graphic arts industry - and it's not over yet.
WHAT DIGITAL CAN DO
Basically, replace anything that is not digital. In some cases, improve it. Certainly, from the environmental point of view, it makes sense to eliminate toxic chemistry and heavy metals from our water courses.
Digital reproduction of images for professional use does this well. The file is captured digitally on a scanner or camera (no film, no processing); it is stored and transported digitally (no dupes, no freight pollution); and is reproduced digitally in the exact quantity required (no chemistry again and no wastage from over-runs).
For the reproduction of quality photographic, art and display images, there are three major technology methods:
* Inkjet - the dominant one and divided into sub-categories
* Electrostatic - "Xerography" or "laser printer" technology
* Dye sublimation - carrier films transfer the colour dyes thermally
All three methods can take files from PCs and Macs, even mobile phone cameras - and reproduce digitally. Electrostatic uses toner 'powder; fused to the paper by heat or other radiation, and therefore is not widely employed for photographic or art reproduction, hence its format is typically restricted to A3+.
Dye sublimation in photographic reproduction is in decline due to costs and versatility issues - fine text can not be satisfactorily resolved for example. It is still popular in the "8 x l0" enlargement market but there are few if any large format dye-subs.
So that leaves Inkjet - the technology that 'squirts' little droplets of ink onto papers, canvas, synthetics and textiles. lnkjet can be divided into:
* Solvent inkjet for signage and outdoor display
* UV-cured inkjet for high durability and printing on thick materials, even doors
* Water-based inkjet for art, photographic, display, proofing and short-term signs
DROPS IN A BIG OCEAN
So, in the high-resolution, water-based, photo-quality digital inkjet market, we have two reproduction methods. Both 'squirt' the ink out, in droplets (known as 'Giclee' in art reproduction circles), but the way they do it differs.
1) Piezo inkjet employs a piezo crystal inside the ink chamber which, when minute voltages are applied, vibrates, causing the ink to be ejected through very fine nozzles. Generally, piezo machines can eject finer droplets and can be managed for colour more accurately, but there are exceptions.
2) Thermal inkjet causes the ink droplets to be ejected by heat. It was supposedly discovered when a Canon engineer left his soldering iron on a hypodermic needle, causing the fluid inside to spit out.
There has been much argument over which is better - thermal or piezo but looking at the quality of results coming out of printers using either technology, it's very much a horses-for-courses debate. Both can deliver superb results.
The thermal camp is represented by models from Canon, HP, Kodak, Encad and Colorspan.
The piezo camp is represented by models from Epson, Mimaki, Roland DG, Mutoh, Océ and Agfa with most using Epson printheads under licence.
A word about the Iris Gicée printer. This was a continuous flow inkjet machine (as opposed to drop-on-demand which all the above are), initially made for proofing publications prior to mass-run printing. Discovering its accurate colour rendering, Mac Holbert and Graham Nash (of Crosby, Stills and Nash fame) established a Giclée art and photo reproduction business in the 80s.
It is still available in the USA but is quite expensive and restricted in format. It is best suited to non-stop art reproduction as the nozzles are firing ink constantly.
DON'T FORGET COLOUR MANAGEMENT
Whatever print method you use, you will need colour management for professional results. Combinations of printer/ink/media behave differently when they reproduce colour. Even two same-model printers from the same factory can print differently so the answer is… ensure colour management is implemented by using ICC profiles for each printer/ink/media combination.
ICC lnternational Colour Consortium) profiles are no longer challenging to produce. The Gretag Macbeth EyeOne system or X-Rite bundles include a spectrophotometer for measuring colour and software for creating the ICC profiles. Don't forget, you will need to profile your computer's monitor too as there's no point in making colour adjustments on screen only to find they don't print that way.
There are excellent packages available that include a RIP and profiling to drive virtually any large format printer. You can print out of Photoshop, but most professionals use a RIP.
THE MEDIA IS THE MESSAGE
It's what you print on that can define the finished result and the choice of surfaces, sizes and substrates is truly amazing - way beyond the 'glossy or matte' choice of conventional photography. For fine art reproductions there are non-wood cotton-based papers of great beauty from manufacturers such as Hahnemuhle. For professional photographers, familiar names such as IIford and Kodak are now making inkjet-coated media as the demand for silver-halide emulsions declines.
Canvas is becoming very popular, with museum grade products making it hard to tell the difference between original and reproduction. Various textiles can be inkjet printed, as can synthetic materials such as thin films and backlit translucent membranes.
Digital reproduction using inkjet technology in its infancy, so climb aboard and enjoy the ride.
This story was first published in Digital Reproduction May 2006.
Andy McCourt is a regular contributor to Digital Reproduction
