Features

There's no lower limit on the number of copies you can reasonably run on a digital press. Some printers advertise 'quantities from one'. That's not to say that orders for single copies are particularly welcome: it's still more cost-effective to output a hundred or more, and you'll be quoted a lower rate for higher quantities. Indigo presses are known to suffer limitations with areas of flat colour and with light tints, showing banding and other unwanted artefacts. Paul Calland, MD of Cypher Digital Imaging Ltd (cypherdigital.co.uk), is open about these issues, advising clients to avoid tints below 10% and large blocks of solid colour. On the other hand, he finds faults occur only with certain combinations. 'We got a problem job recently and I said let's just try it, and it was fine.'

Like other printing technologies, Indigo presses have progressed significantly since the first models were introduced more than a decade ago. Wellington Press had the first Indigo in the UK, and has recently installed the new model 3050. Sales and marketing director Ross Baynham has seen most of the quality issues disappear: 'We're now running a lot of stuff on Indigo that we would have done in litho before.'

A wide range of paper stock can be used, including laid and wove. 'There are boundaries that can be pushed', says an Indigo user who claims to have printed on sandpaper. Ouch. Thin paper can be more of a problem, so if you're planning a brochure or catalogue with a

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large number of pages you'll need to check the lightest weight that can be used, especially if postage costs are an issue. Compared to litho, ElectroInk may be slightly more likely to rub off. Cypher Digital recommends laminating susceptible pieces such as covers, adding a thin coating similar to a varnish. The latest Indigo presses can handle up to seven colours. This means you can request Pantone spot colours, whether for an exact corporate colour or a special effect, in addition to standard CMYK. Another alternative is to use the IndiChrome system (similar to Hexachrome), which prints process colour with six inks, giving a wider gamut within which spot colours can be accurately simulated. You'll need to talk to the printer about this, and going beyond CMYK will narrow your choice of suppliers.

Toner-based presses have their own limitations. Because the toner sits on top of the paper rather than sinking in, it can be susceptible to cracking when folded, and heavily textured papers aren't compatible. If printed pages are fed back through a laser printer (or any process involving heat), the print is likely to come off. This means you may want to steer clear of toner-based presses for letterhead, although there's no problem if you print your correspondence on an inkjet.

Overall, 'the differences are closing up,' reckons e-digiprint's Andy Stevens. With recent presses, 'you don't get much banding and it'll hold quite a light tint.' Toner output is very predictable, and litho issues such as dot gain and misregistration are avoided. We also found that printers using Xerox presses reported fewer problems with jobs not appearing as clients expected, perhaps because of the similarity between the technologies used in the press and on the desktop.

When it comes to finishing, most printers will handle varnishing or laminating, folding and stitching (stapling). Fewer offer perfect binding (with glued edges inside a spine, as in this magazine) and masked varnishes, where a gloss finish is applied only to certain areas using a separate plate.