Digital focus

Liz Grahame deciphers the colour management processes of printing digital images

It’s a sure sign of growing old when you start to experience another significant change in technology in the industry, but there’s no escaping the current transition from chemical to digital photography being used in print.

With digital photography, the finished image is available instantaneously. This compares with conventional photography whereby you can wait a day to see transparencies or pay a premium to speed up the process. And digital imagery has also fine-tuned the approval process in an increasingly digital environment.

Consultancies are now looking at bringing pre-press capabilities in-house to create a totally digital workflow. After initial set-up costs, this undoubtedly saves money longer term on external pre-press costs, and can increase a consultancy’s work rate.

Image quality is a primary concern. Good lighting can go a long way to help, as can a high-quality digital camera. Colours can be manipulated as you go along to create, if required, rich saturated colours. But it is vital designers impose on the photographer how they want the file. At this early stage, images can be sharpened or retouched. And remember, when the photographer is commissioned, the number of shot variations increases more than conventional photography for the same fee.

Transparencies and prints are traditionally used for comparison during the repro stages and at final printing. With digital images, comparisons are possible using a printout from the image. Digital photographers must take extra care to mark the proof for designers accordingly: is it just for composition and content, or for colour as well?

If it is for colour, the proof must be colour managed correctly or it can be an inaccurate match. The colour on the print-out may not be the same as a proof, which will be used for matching when printing. On screen, colour checks are even less accurate.

Worse still, extra costs can be incurred for retouching once printing plates are made. In some cases, the products themselves are supplied to the repro company to match colour as closely as possible to the product.

To avoid a hit and miss approach, a colour management system, or CMS, can be installed. This is the whole process from shooting an image to reproducing it in print or any other medium. The quality-control system will ensure consistency of colour throughout the printing process.

Digital cameras capture an image in RGB (red, green and blue) format, but printing is usually done in four colours: cyan, magenta, yellow and black. Any digital image must therefore be converted before it can be printed.

Conversion is a vital part of the digital workflow and can be carried out by the photographer, designer or printer. When converting RGB images into CMYK images, source (standard) or target (bespoke) profiles – conversion tools – are used. A source profile can be a company’s bespoke standard or a recognised industry standard (the global standard profile is ICC). A target profile is entirely individual to the specific press on which the job will be printed, and gives greater control over colour management and predictability of colour – the ultimate goal.

Checks are needed on what CMYK profile was used, and the type of printer used to produce the proof. A cheap desktop inkjet using proprietary profiles will give a very bright, but un-reproducible result.

As well as photographers having an understanding of CMS and industry-standard profiles, it is vital designers and publishers have CMS in place to maintain the quality and maximise the inherent efficacy of digital images, too.

One of the major advantages of digital photography is the instant on-screen viewing of images. However, these need to be colour managed as well. ICC profiled screens are needed for colour critical subjects such as product colours and people shots, as well as for retouching purposes. Viewing on these screens must be done within ICC compliant software such as Adobe Photoshop 7.

Digital photographers must work closely with designers, printers and repro houses to obtain a complete digital workflow. Most repro houses and printers have many years’ experience in producing a final correct image, and this can be shared with photographers and designers ‘going digital’ for the first time.

The final decision for designers is what to give the printer – profiled RGB for them to convert to CMYK to match the internal proofs, or an already-profiled CMYK file? Talking to the printer will help and will also give an indication of their knowledge of RGB to CMYK profiles and colour management issues.

The introduction of digital photography is challenging the way people have traditionally done business. For this reason, designers must change their attitude as well as their approach to photography in print. The technology and knowledge might seem a lot to take on, but digital photography is designed to make life easier. Moreover, it’s here to stay.

How to manage colour digitally

Image bank Getty Images uses a colour management system, or CMS, to manage its digital workflow, particularly when working with printers. All its photographs are input on scanners using a bespoke RGB profile, or conversion tool. This profile is then used in conjunction with a target (bespoke) profile based on the specific press that will be used to print the job. This target profile is approved and signed off by Getty, and allows it to maintain consistent colour for its digital images, regardless of the printer or press being used.

Digital photography check list

Specify the size and resolution at which the image is being reproduced

Ensure the printer outputs the image before you sign it off, unless it is colour managed correctly, or colours may not match

Commission a photographer with a high-quality digital camera

Brief the photographer to produce both sharpened and unsharpened versions, and always inform the printer if sharpened images are being used

View colour critical images such as brand identities on screens using software compliant with yourself, photographer and printer

Communicate with your pre-press supplier, printer and photographer from the start

Liz Grahame is head of print at Addison Corporate Marketing

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