Colour management in action

As a publication that is striving to ‘drive excellence in print', the Fujifilm team behind PRINT! magazine goes to great lengths to ensure the magazine has high design and production values.

However, in the sprit of continuous improvement, as a team, we embarked on a project to try and improve further still on the finished printed result.  In particular, we thought the images could look a little more punchy and vibrant, just by implementing some relatively simple changes.  I was asked to give an independent view on the magazine and its current colour management workflow.  So, we bought together the designer, Paul Hiscock from HiscockRansom, and from Severnprint, the magazine's printers, Nigel and David Pealing, to discuss this in detail.

The current workflow is created around the designer providing ‘press ready' PDFs to the printer. These are then proofed at the printers for approval by the designer and Fujifilm, a standard workflow process which is followed by most of the industry.  Tone Value Increase (dot gain) compensation curves for the uncoated paper are then added at the rip/platemaking stage by Severnprint.

Start at the very beginning

So where could we improve? I began by asking some probing questions on the colour management process within the workflow. It was quickly established that the images in the PDFs were converted from RGB to a coated CMYK profile on the fly while making the PDF.  Also, as per a previous printer's specification, the PDFs were not produced to a PDF X specification, which would include an output intent to describe the printing condition.

Also Severnprint was proofing to an ISO coated v2 printing condition, which matched the requirements of the PDF, but not the uncoated paper used. It was this proof, when compared with the final result, that had highlighted to all those involved that the images could be improved in the final printed product.  The use of the TVI curve did help somewhat to keep the mid-tones open, but of course the primary CMYK colours and grey balance were not optimum for the paper used.

Now at this stage you might be may be thinking that we are being very honest here and that perhaps some if not all involved parties should have known all of this already. 

Well, in reality, using a specific uncoated colour profile and colour managed workflow is still not common practise for printers or clients. Even when using the ISO 12647/2 standard printing conditions, many clients will use coated profiles despite the fact that the work is to be printed on uncoated papers. Printers will still often try to use these files which then lead them to believe that uncoated papers are difficult to print.  This is because if the files are not prepared for printing on uncoated papers there will always be issues with matching proofs on press, ink not drying and with marking problems as well.

Next steps

The starting point was to examine the combination of paper, printing process, press and ink. PRINT! is produced on a sheet fed litho print using ISO 2864/1 using compliant inks for ISO 12647/2 2008 Amd 1 standard printing conditions and on an ISO Type 4 uncoated paper.  In light of all these factors, I recommended a new CMYK separation profile, a profile based on the latest Fogra 47 dataset (see box out) for ISO type 4 uncoated papers. The profile chosen uses GCR to provide stronger black separations and an lower total ink coverage (TAC) of 280%.

I created a custom colour settings file with this profile, for Adobe CS, which was loaded into the designer's copy of Adobe CS. Also a custom PDF job options file based on the PDF X1a specification was loaded onto the designer's computer.  This provided page PDFs that are specific to the paper, press and ink combination.

Proofing for this issue was carried out in Fujifilm's showroom in Bedford using its digital contract proofing system, simulating uncoated paper and the uncoated ISO printing condition based on the Fogra 47 data set (again, see box out).

It was noted early in this process that the paper colour of the Cocoon Uncoated was a little ‘whiter' than the white paper colour in the Fogra 47 based profile. There are a number of technical answers to correct this. We could have edited the CMYK profile to match the CIE Lab values of the paper. This can be used with successful results, but would need a new proofing queue with this profile as the ‘simulation' output profile.

So as the ‘brighter whiteness' of this paper is manly caused by optical brighting agents, (OBAs) and the fact that the -b Lab figures for the profile and the paper were within three of each other, we took a differing approach available to us in the Fujifilm digital proofing system.  This was a simple alteration within the proofing rip to adjust the paper white to match the production paper.

By implementing these seemingly minor changes, what we ended up with were images, PDFs and proofs that were colour managed throughout the workflow to reflect the uncoated paper.

Our printer Severnprint was then able to use in rip TVI compensation curves more accurately so as to match the required TVI - ISO curves C for CMY and curve D for K.

Severnprint was then required to run to the CIE Lab uncoated values in ISO 12647/2, using process control software to monitor the press run against these requirements.  This type of CMYK profile for uncoated paper also helps with colour stability on press, meaning that the printed sheet will dry quicker and so is less likely to mark on press or in finishing, and uses much less ink as well. 

What is a data set?

So what is a data set, or more accurately, a colour management data set? It is the colour data read from a print test run, in the case for the ‘ISO CMYK profiles, carried out by Fogra, the German Graphic Technology Research Association, which is based on the ISO standard printing conditions for a paper, press, printing process and ink. In the case of PRINT! magazine, an uncoated paper, offset litho and ISO 2864/1 inks.  From this data set, colour management profiling software is used to produce an CMYK ICC profile.

The coated paper, ISO Types 1 & 2, offset litho data set Fogra 39 is unfortunately often referred to as an ICC profile, or as the printing standard. As can be seen from the above, this is not the case. The standard is ISO 12647/2 2004 Amd 1 2007

To request your copy of PRINT! and to see for yourself if we've achieved optimum results, contact marketing.fgs(at)fuji.co(dot)uk