Colour has always been a complicated issue and something of a sacred cow, demanding love and attention from the experts to get it right. That’s all changing now as the black art of colour control succumbs to automation and the adoption of standards just many craft-based skills that have gone by the wayside.

With more and more firms looking to adopt printing specification ISO 12647, the award has highlighted the importance of matching the right CMYK separations to on-press performance. Not all CMYK is created equal – even if it’s intended for the same printing conditions – and a different CMYK breakdown may pass muster on proof, but prove a problem on press.

At its most basic, ColorServer has a part to play in ironing out those inconsis-tencies by standardising separations. That makes a minder’s life much easier as they can be sure that, if a sheet has got images from a mix of sources, all have been rebuilt to behave consistently – meaning that when the ink keys are adjusted, there are no surprises and fewer compromises to get the best overall result.

ColorServer’s ability to separate from RGB to CMYK, or reseparate CMYK-to-CMYK and to map spot colours to the available gamut of any printer or press, isn’t just a tool for printers. It is equally useful in a large studio preparing output for many different print processes, or a repro house tailoring work for output in different publications, geographies or processes, as it is at a printer taming inconsistent separations and optimising the output from different machines to produce consistent colour across them.

RIP compatibility
In the 4.6 version of ColorServer, there is extra power to make it simpler to use and more suitable for today’s businesses, which are likely to have multiple print processes and machines that all need colour matching. The product has also become more than just a colour control tool. The incorporation of the Adobe PDF Print Engine (APPE) into ColorServer gives the ability to control the PDF it outputs and flatten transparency, which can help ensure compatibility with older RIPs and alleviate the need for additional investment elsewhere in the workflow.

“Not only is there a colour management benefit, there’s also a cost-saving benefit because you don’t need to upgrade all your RIPs,” says GMG area sales manager, Oceania, Garry Muratore. It simplifies the workflow with new hot folder-based functionality that makes it possible to support multiple presses and printers, and to keep then all calibrated.

“Before it was a hassle to match multiple devices, so we developed SmartProfiler,” adds Muratore. “Now, you can calibrate from the hot folder, and more importantly it opens up the software to anyone, even those with little colour skill.”

With ColorServer and SmartProfiler, it is a simple process to characterise any output device, but especially digital presses and wide-format printers that may use additional colours to the standard CMYK set, such as an orange, green or violet or light cyan, magenta and black. In fact, SmartProfiler was developed to make the product more suitable for digital and wide-format. And it’s not just about characterising different devices, it’s possible to characterise how different substrates interact with any printer or press to ensure consistency across a range of media.

For any application, where supplied jobs have special and spot colours, it is simple to reseparate to get the best possible match based on the colour gamut of the output device using the built-in Pantone library. It also simplifies the handling of colour, as all the colour management is done in ColorServer.

“I’ve seen a lot of RIPs in my time and none can handle colour as powerfully as ColorServer,” says Muratore.

ColorServer developed out of a product called CamFlow, which was designed for separating RGB tiles from digital cameras into CMYK. In practice this didn’t find much favour as it was a niche product and putting separation into the hands of the photographers turned out to be less than ideal, as they didn’t really understand what they were getting into. So the product evolved into a colour workflow tool capable of doing RGB-to-CMYK and CMYK-to-CMYK conversions for standardising colour.

At the heart of ColorServer are the tools that GMG uses in ColorProof to produce contract-quality proofs on inkjet printers. These include its MX3 and MX4 files, which describe the colour gamut and reproduction of each device, and which are used for the colour calculations. These data files can be fine-tuned using the Colour Value Correction (CVC) tool. This gets right to the heart of GMG’s approach and allows fine-control of critical colours using a colour manager’s expertise and judgement rather than just the numbers produced by a spectrophotometer.

“The CVC enables individual control of the colour values to make proofs match the press sheet,” adds Muratore. “The three- and four-colour greys – especially in the highlights – are where people are most sensitive to variations.”

So, although the software uses colour theory to automate many processes that used to rely on a skilled retoucher-come-colour manager, it also acknowledges the shortfall of a purely numerical process and provides a best-of-both-worlds approach that uses human skills for tweaking results more accurately to be embedded in an automated workflow. “Just getting the delta Es down is not enough – you need to use colour tools sympathetically to what you want to achieve and to provide a colour match,” says Muratore.

Unlike most colour tools out there, GMG opts for ICC technology for its colour processing in favour of its proprietary 4D colour processing technology, which it claims is the key to its success in being able to provide results that measure up. “It’s a proprietary technology, but can work within an ICC workflow if it needs to,” explains Muratore. “However, most people don’t use ICC once they’ve installed GMG.”

At the heart of the 4D technology is the understanding that ICC-based approaches do not necessarily protect the purity of each colour separation. Working in the Lab colour space disregards the separation, which can destroy the black channel and introduce problems in the primaries and secondaries.

Range of new features
Another new feature of version 4.6 is improved gamut mapping, which is how the software will produce reproduction on a machine and substrate combination where there is a smaller available range of colours than is assumed in the supplied file. “It uses an intelligent mix of colorimetric and perceptual techniques, which is better than most retouchers for CMYK-to-CMYK; it’s awesome,”
says Muratore.

One area that often goes hand-in-hand with separation optimisation is ink optimising, where the software rebuilds the separation to minimise the use of coloured inks by substituting black where possible to save on ink usage with the attendant cost and printability benefits. ColorServer itself isn’t an ink optimi-sation tool, but GMG does offer a separate standalone product, InkOptimizer, which can be used alongside ColorServer, including running on the same hot folder in an automated workflow.

The product comes in several versions, depending on what suits your needs.

All include profiles for common output colourspaces such us the Fogra 39L characterisation of ISO 12647-2, but if you need to create custom profiles to describe a non-standard space you need the Pro version, which includes profile editing.

SmartProfiler is available in a bundle with ColorServer, and is intended for firms with multiple printing technologies so, if you’re a purely litho printer, it’s not necessary, but if you have any digital machines, or multiple digital or wide-format printers, it is necessary to ensure the best output from each machine. GMG also offers a version of ColorServer as a service. It’s not a hosted online service – GMG supplies a server for the software that is installed on your premises, but you rent the system monthly, and keep the package and any profiles GMG has created for you at the end of the term.

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