My adventures with ISO 12647-2 and colour management

Now that the BPIF UK ISO 12647/2 certification scheme is, at long last, in place with its first UKAS accredited certifying body, Print & Media Certification, the first such third party certified scheme for ISO 12647-2 in the world, I have been musing on my time working with the standard and colour management. Hope fully my memory is sound in the area, but errors and omissions are expected,

 I could not bring myself to call it a journey!

When I started my consultancy in 2001 initially the main business came from managing computer-to-plate projects for printers. But I was very aware that pre-press as a business and as a function was going up stream into the hands of the printers clients: graphic designers, publishers, corporates and government.

 The drivers for this change, at this time were the adoption of desktop publishing software, PDFs used as the file format of choice, and the increasing use of digital photography in the early 2000s.

 By the mid 1990s typesetting, as a separate trade and function, had ceased to exist.

Who now who receives any large number of transparencies or colour prints to scan?

 So the scene was set for the client to take over the technical production of pages, but what was missing?

A colour managed workflow from image to page to PDF to contract proof to press; this was missing.

So when starting two large projects in 2001 to internalise pre-press  for an auction house and a specialised publisher the gaps in this area quickly became an issue. The colour skills of scanner operators and retouchers were no longer available in this environment.

There was a lack of confidence and knowledge about digital images; how they were viewed, selected, approved, converted to CMYK and contract proofed.

 Digital contract proofing at this time was based on the ‘DuPont Digital Chromalin’ standard’ which was vaguely based on the little understood and very loose Euroscale coated CMYK profile and specification.

Using the newly available inkjets printers with proofing RIPs such as GMG and BestColor, the only reference to match seemed to be a Chromalin?

 Choosing the correct CMYK profile for a printing press and paper was also difficult: there where a number of profiles named as `Euroscale coated or Eurocolour but there was little information about the figures associated with these profiles.

 So what does a worried but conscientious consultant do in this situation? Lots of research.

 The use of ICC profiles and workflows was key to the process, that was very clear. So using Adobe InDesign, Photoshop and Illustrator, which were ICC colour management aware, was important. As was using calibrated computer screens, at that time CRT monitors, the good ones were very expensive, even when compared to todays high end LCD screens. Barco, Sony Artisans and the LaCie ranges were used.

However, until I found ISO 12647, the correct CMYK profiles, printing condition, how to calibrate and control digital proofing was still unclear.

After the usual web searches I found ISO 12647/2-1996 standard printing conditions for offset litho, and part 7, the digital proofing standard, the German PSO (Process Standard Offset) from Fogra and information on its application. Then I attended a number of conferences in Europe to gain more information on ISO 12647 and its practical application.

ICC CMYK datasets and profiles for ISO 12647/2 were freely available and some of the digital proofing software vendors were upgrading their systems to use ISO 12647-7 digital proofing calibration and verification, using the ISO 12647/2 based CMYK profiles.

This 1996 version of the standard used the Fogra 27L dataset for offset litho using coated papers, the most popular profile from the dataset being ‘ISO coated (ECI), made available by the European Color Initiative. Rather confusingly these early ‘ISO’ profiles where available as two kinds, for measurement with a white stock paper backing for heavyweight papers and a black paper blacking for lightweight papers!

This completed the final part of the colour management workflow: proofing and printing.

 These profiles were used within the workflows for the auction house and publisher. The inkjet proofing systems incorporated the ISO 12647/-7 requirements. The next stage was to brief the printers: remember this was 2002! 

Over a series of meetings, visits and press trials the contracted printers were ‘encouraged’ to work to the standard. This was very new to all involved. The use of CIE Lab values for CMYK in place of ink densities, measuring TVI (dot gain as it was called then) and using in -RIP curves to change it to the requirements of the ISO-based CMYK profile, all seemed very strange to the printers involved.

Also this was before the use of process control software such as Bodoni PressSIGN and MellowColours PrintSpec (other brands are available ;-)).

 The measurements were done using a handheld spectrophotometer, one by one. A speadsheet was used to calculate dot gain compensation curves.

 However, it worked: the printed work matched the contract digital proof, which matched the CMYK PDFs on screen. The conversions from the RGB image to CMYK were as good as they could be.

What was more encouraging was that all the printers involved changed all their production to ISO 12647-2 within 6 months. Again this is still 2002 we are talking about.

 These printers are all now heading towards the BPIF accredited certification scheme for ISO 12647-2.

Soon after this the revised ISO 12647-2/2004 was released. This enabled Fogra to make available colour management datasets including Fogra 39L for coated papers printed by offset litho.

Only one profile was needed: the difference in heavy and lightweight papers was covered by a small difference in the CIE Lab values required when measuring on white or black backing papers.

By this time all my projects were using ISO 12647, mainly still part 2 and 7 for proofing, as the final part of the colour-managed workflow. Existing clients were changed to the profiles based on the revised standard and profiles.

 At IPEX in 2006 a UK TAG (technical advisory group) for ISO printing standards was launched. This has enabled the UK to influence the development of the many printing standards in place and in development in a formal way via the British Standards Institute

Also at this time the BPIF formed its Technical Standards Committee in order to review, influence and communicate better with its members in these areas.

 One of its first projects was to compare the relative merits of the ISO TVI (dot gain) based process control with the US IDEA Alliance G7 ‘near neutral gray balance’ method. Follow this link for the report.

 Since then UK printers, sometimes led by their clients, have increasingly adopted both colour management and the standard printing conditions covered by ISO 12647.

 In 2010 after two years work by a working group from the BPIF Technical Standards committee, the worlds first, third-party accredited, product based certification for ISO 12647-2 was launched. As referred to above the final element is now in place.

I am part of the both the BPIF Technical Standards Committee and the UK TAG for printing standards and know how slowly processes and change seem to happen in the standards world. But as Chair of the BPIF ISO 12647-2 certification steering group I am now very pleased that after all this time, the UK now has a world leading scheme for printed product quality.

 Do not ask me why it took so long without a full, good bottle of white wine and two glasses in your hand!

So what next? The standards continue to be revised to meet the ever-changing needs of the industry. I guess the next big one will cover the digital printing areas. This is work in progress at the moment within the ISO TC130 committees. It is a very wide and increasingly complex subject, covering the many types of digital printing.

 Colour-managed workflows have become more common over the last few years. Often in the hands of the printers client where providing colour-managed PDF X files and certified proofs using ISO 12647-7 has been embraced by many print purchasers and specifiers, large and small. Indeed Adobe CS, used correctly with the correct colour management settings, is a pre-media shop in a box.

However, where and when and how colour management is applied is becoming a complex issue. In many ways this is as much a management problem as a technical one.

The use of very clever colour management server-based software’s can automate all colour management, but the workflow must be clear and transparent to both client and suppliers.

Who does what to whom and for what purpose must be clear to all parties in this workflow.

File, images and PDFs produced and even proofed for a given printing condition, printing method and material will need to be repurposed if these parameters change. Often new contract proofs, on screen or physical, will be required.

 Repurposing for other media-the Internet, mobile, digital outdoor advertising, etc.- brings many new colour challenges for clients, brands and producers.

But this is not happening generally in the industry, so it will be, with digital printing, the next big area for colour management and ISO printing standards to address.