But what about that sales multiplier colour? Is the equipment available? Is it economically viable? Are companies doing it? Book manufacturing is one of the success stories for digital printing and it is expected to grow over the next five years or so. The same goes for newspapers. Admittedly, here the growth has not been as great as was originally expected, but now that changes in file transfer processes have made the movement of newspaper content around the globe that much easier, the technology is definitely finding a place in niche out-of-territory markets.

The forecast growth in both sectors is not surprising really as digital printing offers a number of advantages. Taking books first, it has meant that titles become more easily available and need never be out of print. It can also mean that books can be published which would not see the light of day with traditional presses due to the production costs. In addition, ultra-short runs become more viable, such as for review copies and for sales purposes.

Probably even more importantly for publishers, the technology offers just-in-time (JIT) production and thus virtually eliminates the need for inventories. As economic run lengths can be shorter and hence be carried out more often, digital printing can also significantly reduce the percentage of books that have to be pulped: as much as 30-40 per cent of books sent to bookshops can end up as returns.

It is for reasons such as these that many of the major European and American book manufacturers now have a digital printing section and continue to invest in it. For instance, the recent installation of an IBM Infoprint 4000 printer at the King's Lynn factor of Biddles in the UK, the book printing arm of W&G Baird Group, has increased its capacity to 30,000 books a month: the company specialises in the production of monochrome and two-colour limp and cased books.

We have also seen the arrival of companies offering a books-on-demand service such as Lightening Source. With its production sites in the UK and the US, it produces around 500,000 books a month for 2,000+ publishers. So obviously there is a demand for digitally printed books.

With newspapers, the benefits of digital printing are just as strong, but they are different. Basically, it enables publishers to build new businesses rather than expand existing market sectors.

One of the most important benefits is earlier availability in remote international markets. This allows readers to receive their newspaper on Day A rather than Day B or even, in some cases, Day C. Publishers can also open up markets previously not possible due to the small number of copies required, at least at the outset. Another benefit is the ability to produce supplements with local editorial and advertising, which can be sold with the main newspaper.

Digitally printed newspapers can also be personalised or tailored for a targeted audience, both in terms of editorial and advertising. A good example of this is the customisation of copies for airline passengers, something that the Guardian is doing with Qantas airlines.

Then there are the repurposing applications. Here, publishers can capitalise on their greatest asset - their newspapers' content - by launching new publications that reuse existing content. One example of this is the 100 Years of the Tour de France supplement that was recently published by the Belgian-based media group, Het Belang van Limburg, which publishes the newspaper with the same name, as well as the Gazet van Antwerpen and the free daily Metro, amongst other products. The supplement, which was based on newspaper cuttings and consisted of 48 stapled pages, was printed on newsprint using an Océ VarioPrint 3090 digital printer for the main monochrome body and an Océ CPS 700 for the full-colour cover.
Colour conundrum for books

This brings us nicely to the main subject of this article: the importance or otherwise to these two sectors of digital colour printing and its viability, both financially and technically. In other words, would their growth be greater if full colour were to be used throughout, and is it possible?

Returning to the book manufacturing sector, digital colour printing is currently being used but not that much.

For instance, there is the very short-run production of review and marketing copies of full-colour trade books for the publishers' sales forces. There is also the occasional children's book that is being printed digitally, though this tends to be for niche markets such as personalisation. For instance, Butler & Tanner are producing such books in conjunction with certain British football clubs.

In fact, the area that is seeing the most use of digital colour printing is book covers. For instance, Lightening Source in the UK has an IBM Infocolor 70 and an HP Indigo 1000 to do this work, while in the US it has two HP Indigo 3000 digital colour presses and an IBM Infocolor 70.

It is also one of the reasons why the Xerox iGen3 has been installed at Henry Ling and Friary Press in the UK: both book printers are based in Dorcester. At Henry Ling, they also use the iGen3 to print a few inside pages in some of the books. However, as the company specialises in scientific, technical and medical small-to-medium (STM) run length publications, there is not that great demand for inside colour.

Indeed, this is a main stumbling block in the use of digital colour printing in book production. On the one hand, the technology and even the economics can work out for the production of short-run books such as those in the STM sector, but there is little demand for colour. On the other hand, with trade books - where there is the greatest demand for colour, especially for 'coffee table' and children's books - the run lengths tend to be that much longer and the cover price significantly lower, making digital colour printing much less viable.

So, this is where we come up against the two main constraints with using digital colour printing in book manufacturing, that is to say the speed of the machines and the cost per page. In addition, with coffee table books, the images are more important than the text and, however much a convert to digital printing you are, it cannot be said that it can offer print quality as high as the very best of litho.

Taking the production speed first: in comparison with even monochrome digital printers, full-colour digital presses are slow. For instance, the continuous-fed CR2000 monochrome printer, which Delphax Technologies launched at the May 2004 Drupa exhibition in Dusseldorf, can duplex print around 2,000 8.5x11in pages a minute. In addition, its format allows the production of three-up 6x9in books, while its electron beam technology and 600x600dpi resolution makes the quality suitable for book production.

This compares with, say, the HP Indigo 5000 and the Xeikon 5000, both of which were also launched at Drupa, but neither machine is faster than its predecessor, running at around 7,800 pages an hour maximum. Admittedly, both of the new machines can handle increased volumes due to improvements in reliability and maintenance, and in the case of the Indigo, improved paper handling and ink systems. They are also more cost-effective. For instance, the Xeikon 5000, which has a new digital front-end, is said to be suitable for monthly volumes up to three million A4 full-colour pages at a cost of e0.02 per page though the figure drops to 1.5 million in commercial applications where the paper needs to be changed frequently and runs are of medium length.

In other words, they have become more like the digital colour presses that are generally called second-generation - that is the Xerox iGen3 and NexPress 2100 - whose quality is more like offset. In fact, according to the organisers of last year's British Book Design and Production Awards, the digital section was judged according to "traditional standards of colour, design and production".

Interestingly, the winner was a book featuring images of paintings by international artist Sannie Draw produced by Selwood Printing, the digital printing arm of Butler & Tanner, on the company's NexPress 2100. So it is obvious that the use of digital colour printing for book production is widening, but there is another factor in the equation that has to be taken into account, and that is the fact that just as digital colour printing is becoming more cost-effective, computer-to-plate technology and more automation means that economic runs for traditional offset presses have dropped significantly.

For instance, Chippenham book printer Anthony Rowe, which handles runs from one to 25,000 copies and has a print-on-demand subsidiary in Eastbourne using digital printing, says that litho can now compete with digital printing for runs as low as 200 because of press automation. Similar figures are given by Henry Ling.

Admittedly, the majority of the books that these companies produce are academic or educational and, as has been said already, have little demand for colour. On the other hand, the crossover point between digital and offset for colour is currently thought to be around the 600 mark. This is significantly lower than it was a couple of years ago and it is expected to drop another 100 copies in a year or so.

However, by then, we could well have seen another step change in digital colour printing with such systems as the Océ VarioStream 9000. A continuous-fed printer, its main feature is its ability to expand from monochrome to two-colour and even four-colour printing by adding up to four additional colour stations to the basic model.

At the heart of the 9000 is the Océ single-pass technology, which enables both sides of the substrate to be printed simultaneously and then fused in a non-contact, single-pass infrared process. As a result, it can print substrates of 36-240gsm at 240-600dpi at 59.2m per minute, the maximum format size being 482.6x711.1mm.

However, so far there are only two versions of the series available: the 9210 monochrome and the 9220 2/2 colour models, which also has the functionality of the black-and-white version. In addition, no timing has been given for the availability of the four-colour machine, although the company says that its development is "already well underway".

In the meantime, it might also be worthwhile checking out Kodak Versamark, the new name for Scitex Digital Printing, after its recent acquisition by Eastman Kodak.

There are two reasons for this.

Firstly, there is the fact that the company plans to show its next generation of Business Color continuous inkjet printhead technology, which produces ink droplets one-third the size of its current machines, resulting in sharper images and a wider colour gamut. The technology will be used in the company's high-speed VX5000 press.

The second reason to check out Kodak Versamark is the potential impact that Eastman Kodak could have on the company. For one thing, there is its background in full-colour inkjet digital printing: its subsidiary, Diconix was demonstrating such high-speed capabilities back in 1980. For another, there is the potential both in terms of hardware and consumables to lower costs, due in part to purchasing power but also due to its consumable manufacturing capabilities.

The colour quality might not be there yet for many of the full-colour titles being published. However, Eastman Kodak also has considerable expertise in colour technology and colour management, and we could also see some significant changes here in the next couple of years. In fact, Kodak Versamark is already claiming that its new printheads offer a viable replacement for some offset work such as newspapers.

Newspapers

In fact, the outlook for colour in digitally printed newspapers does look brighter than for books. For one thing, traditionally produced newspapers include an ever-increasing amount of full colour, and readers in remote markets tend to want their digitally printed newspapers to be as near as possible to the home edition. In addition, according to research undertaken by the Guardian, readers who are more than five hours' travelling time away from their home country regarded up-to-date news as being more important than print quality or value for money.

Versioning

One of the concepts that manufacturers such as Océ believe will give a push to digital printed newspapers is the ability to have local advertising. Here again, colour will make a difference. Probably even more importantly, not only do advertisers want their adverts to appear in colour but they are prepared to pay significantly more for it. Indeed, it has even been suggested that it could mean that colour newspapers with paid advertising could be sold for less than black-and-white ones.

Will it work?

So the market demand for colour is there, but what about the available technology and the economics? Here, one has to differentiate between those newspapers that are digitally printed on demand and those that are digitally printed but distributed traditionally.

In other words, there are the newspapers which are printed individually, as in the case of the 170+ kiosks set up by Satellite Printing where it takes two minutes to print a copy of the selected newspaper in A3 stapled format. Then there are those which are printed in - albeit relatively short - production runs, as with the Océ printer partners around the world which use the Océ Digital Newspaper Network.

In the first instance, relatively slow-speed cut-sheet digital printers as are offered by Xerox tend to be used. The colour versions of such machines are not only printing increasingly higher-quality colour; the cost of consumables is coming down. However, as yet, it has not come down sufficiently to justify colour newspapers. In addition, there is the speed factor. Not only are the colour machines slower but there is also the problem of having to distribute and print the much larger files involved with colour.

There are similar problems when it comes to the digital print and traditionally distributed scenario. However, the technology is advancing.

There is for instance the already mentioned Océ Variostream 9000 with its future potential to have four-colour printing stations added to that of the monochrome. Admittedly, the press is slower than the Variostream 7000 that is currently being used to digitally print newspapers. We also do not know when it will be available and how cost-effective it will be. On the other hand, the 9000 series can offer higher print quality and less toner usage resulting in lower costs. In addition, the 9220 version with its 2/2 colour capability means that at least spot colours can be used.

There is also, again already mentioned, the new Kodak Versamark printhead technology. Indeed, it is understood that a German newspaper is already digitally printing editorial pictures and adverts in full colour using a Scitex web-fed system capable of printing, cutting and folding a broadsheet newspaper.

However, the format is limited, requiring the broadsheet to be reduced by 10-18 per cent, while a loss of picture quality can occur due to the need to keep the file size to a minimum in order to obtain an acceptable delivery speed. More significantly though, due to the high capital cost, it is reckoned that around 6,000 newspapers a day need to be printed on such a press for it to be financially viable.

In other words, as the output is only 400-500 newspapers an hour, the production window has to be quite wide - something which is difficult to organise in a newspaper environment. It is also worth noting that despite having printing plants in London, Johannesburg, Sydney and Spain, Océ says that currently a total of around 7,000 newspapers are printed on average each day.

On the other hand, there are other manufacturers who are developing systems for the digital printing of newspapers. For instance, this sector was one of the ones mentioned when Agfa recently announced that it had been working with printhead manufacturer Xaar for the last four years developing a new range of high-specification inkjet printheads, and that it had now signed a strategic agreement for joint research, development and manufacturing of these printheads covering a five-year period.

Described as a major step change in inkjet performance, the new heads will be versatile enough to cover 80 picolitre (pl) droplets for high-speed inkjet needs down to three picolitre droplets for high resolution and fine detail. They will be available as greyscale or binary versions firing 382 or 764 channels.

The technology was previewed at Drupa, with printhead manufacturing taking place at Xaar's plant in Sweden, which has had a £1.6 million (e2.27 million) boost from Agfa. Xaar will sell the printheads under its OmniDot brand but Agfa, as a secondary development, is looking to use the technology in graphics sectors including newspapers.

Of course, it is early days for such technology and it will be some time before the economics involved will be known. However, when it is considered that even for international editions the average price of the Guardian, for instance, is e2.80-3.50 and for the Observer it is e3.50-5.00, we are not going to see digital colour printing being used for full-scale production for many years, if ever.

In fact, NexPress's CEO Venkat Purushotham nicely summed up the position at Pira's Digital Print World conference in December 2003 when he said that digital colour printing will normally only be used early in a document's life, such as for book review copies or a new newspaper market, and at the end of its life, as in the case of reprinting out-of-print books or repurposing newspaper content. In other words, it will complement not oust traditional offset and the ideal set-up will offer both options.