It’s a measure of just how hot a topic colour is at the moment that when the BPIF held its second annual colour conference in September, people had to be turned away because there was no space for them at the venue.

　　The current interest in colour is the move to implement the ISO 12647 specification for colour printing, which is also sometimes called Process Standard Offset (PSO). It’s not a new specification. It came into being in 1996 and was revised in 2004. A further revision to take account of the market’s feedback and the advances in technology, methodology and process control is expected any day now.

　　“It’s into the mainstream now,” says Aaron Archer, Pureprint group technical manager and member of the BPIF Technical Standards Committee, who prepared the BPIF Colour Toolkit, A guide to colour management and standardisation.

　　Archer implemented the standard within Pureprint’s companies, including Beacon Press two years ago and, before that, at his previous employer Butler & Tanner. While they are large specialist operations with a reputation for delivering top-notch colour quality, he reports that the use of controlled colour is becoming commonplace now, citing a recent visit to an average B2 printer, which has taken on board colour control.

　　Why is there currently such a clamour for knowledge on colour, when previously the intricacies of its control were left to a few experts and especially interested printers who could happily discuss delta E and Lab values with impunity?

　　“The nub of the problem is reducing cost through less waste and more saleable product,” says Paul Sherfield of the Missing Horse Consultancy, who is one of the colour specialists being kept busy at the moment by the interest in controlling colour. Sherfield undertook his first implementation of ISO 12647 for auction house Bonhams and its roster of four printers back in 2001.

　　According to Pureprint’s Archer, cost isn’t the only issue. It’s also about being able to win and retain work. Print managers are increasingly demanding it of their printers as a way to ensure a consistent quality product to their clients regardless of where it is printed. Williams Lea led the way, but others are adopting it as part of their printer selection processes.

　　And it’s not just print managers. Discerning corporates are seeing it as a way of ensuring their brand colours are more accurately reproduced. Archer defines the benefits for Pureprint as being shorter makereadies, improved customer satisfaction, less spoilage, time saving throughout production and as a marketing tool that can help win custom.

　　Several things have come together to make now the right time to adopt PSO: CTP, colour managed digital workflows; digital images; and the uptake of digital proofing to measurable standards. And most modern presses have some form of closed-loop control on the press console that, by using spectrophotometric or density readings, can keep the colour delivered consistently.

　　Hitting targets

　　There’s also been the development of tools to help implement the specification ranging from the methodologies, implementation guides and target data sets (from the likes of Fogra and Gracol) to the burgeoning software tools to help implement standard colour and then keep it in check. Firms that have been addressing this problem for several years, such as Mellow Colour with its ISOLitho product, have been joined by players such as Bodoni Systems, with PressSign. More recently, proofing providers have entered the market including GMG PrintControl (PrintWeek, Product of the Week, 18 October 2007) and the just released Oris Certified Press from CGS.

　　These latest products have all come from firms that have made their names in taking standard inkjet printers and characterising, calibrating and colour managing them to turn them into proofers. Proofing by its very nature needs to be consistent and to a known and controlled standard day-in, day-out. Previously, the press tended to be treated differently and time was spent ‘painting’ on press – that is trying to get a good match to a proof or the client’s interpretation of the job in their mind’s eye. With standards-based colour managed proofing in place, there is less disparity between what’s on the proof and what comes off the press, which should take away the thankless task of attempting to match the unmatchable.

　　“It’s about getting printers to think about their press in a whole new way – as an output device,” says Sherfield. “We’ve done it for years on proofers and film and plate processors. But never on the machine that brings in the bacon – the press.”

　　He points out that you do need to have that control all the way through the process to make it work. “You need a colour management policy. Even if you print to a standard, that’s no good unless you get reliable colour in.”

　　As was found when moving from film to CTP, PDF and digital workflows, the process of migrating to a new way of working isn’t always as smooth as it could be and tools are needed to help the transition. The need for reliable PDF files led to the development of specifications, such as PDF/X and Pass4Press, and the uptake of pre-flight tools, such as Enfocus PitStop and Markzware, that can flag up, and sometimes solve, problems with PDF and application files. Software that provides a similar solution to the colour issues is now available.

　　Pureprint’s Archer is looking at the available tools, which include products such as Alwan CMYK Optimizer and GMG ColorServer. “If you’re applying ICC profiles and are pushing them up the chain, then you don’t need them,” he says. “But you’ve got data coming in that might not be right, so you need tools for colour pre-flight and normalisation.”

　　Sherfield sees another application for these tools in repurposing archived jobs to make sure that they run efficiently once you’ve moved to process standard offset, without having to break off from your nicely set up standard conditions. That repurposing can be quite radical, according to Archer, with the possibility of taking a job set up for coated paper and automatically converting its separation settings for uncoated or vice-versa. This process of adjusting the separations is nothing new. It is something currently done manually in pre-press, but the ability to automatically adjust jobs either to re-purpose them or to correct something supplied out of spec is a new and powerful tool.

　　It is paper where Archer feels there are still shortcomings in the ISO specification and from paper suppliers’ response to ISO 12647. The new version of 12647 is promised to better address the paper issues. Archer also wants the mills and merchants to label their stocks in accordance with the ISO 12647 specification to simplify their selection.

　　Inks are easier as the requirements for a suitable ink are set out in ISO 2846, and firms including Sun Chemical and Stehlin Hostag have developed suitable products.

　　With the increased uptake and interest from buyers, the time has come to embrace Process Standard Offset if you don’t want to be left outside in the cold like one of those unlucky delegates at the colour conference.

[时间：2007-12-21  作者：Barney Cox  来源：信息中心]