Using the Fogra 39 and 47 datasets for coated and uncoated [...]]]> Some of the other colour geeks around will have been aware of the the resent work by VIGC, the Belgium printing industry research group, on ISO 12647/2 CMYK profiles with very low TAC (Total Area Coverage) and high levels of GCR (Grey Component Replacement).

Using the Fogra 39 and 47 datasets for coated and uncoated papers they produced a series of profiles with decreasing TAC and increasing GCR.

For each paper type there are 4 different TAC values 220%, 260%, 300% and 320%. The profiles were generated with X-Rite i1 Publish profiling software.

Some of these profiles look interesting, not to say challenging and radical, especially the 220% and 260% TAC version for coated papers.

I have been using Fogra 39 and 47 based profiles with GCR for differing needs; printing on lightweight coated papers, producing 4 colour black and white separations with a stronger black, so giving greater stability and neutrally on press; but have never ‘pushed’ the TAC and GCR boundaries into these areas!

So with the help of two long-standing clients, I decided to test the 220% and 260% TAC coated profiles against the ISO coated v2 profiles more commonly used.

I created a A4 test page in Adobe InDesign, using ECIRGBv2 images and saved four PCF X1a files, using the 220% and 260% TAC profiles from VICG and two, more standard, ISO coated v2 profiles with 300% and 330% TAC.

The four pages were proofed at Bonhams the Auctioneers design and prepress studio in London, using an EFI XF colourproof rip running Epson Stylus Pro 7900 Spectroproofer printers with inline spectrophotometers and proof verification to ISO 12647/7.

The proofs were all verified and had an average De of 0.80 and a maximum De of 3.08.

When compared by a number of professional observers under controlled D50 lighting they could see no difference between the four test pages and profiles. Very impressive so far, and as VIGC reported.

The four PDF X1a files were also ‘soft proofed’ on an Eizo ColorEdge CG243W monitor and again no difference could be seen. However, as would be expected, when looking at the separations the difference in the black ‘seperation’ was marked!

Screen grabs for the seperations:

The three screen grabs above show the CMYK results, the CMY separations and the black separation. The 220% TAC profiled image is on the left, the 330% TAC profiled image on the right.

So the next test had to be to print the four pages. While the digital contract proofs and the soft proofs showed that the four profiles give the same colour appearance I was uncertain how they would work on a litho press!

Would the lower ink film coverage on the 260% and 220% TAC effect the gloss of the printed result? 

Witherbys/Lithoflow Printing, the oldest printer in London, dating back to 1740, but with technology firmly in the 21st century offered to help. They imposed the four test pages and imaged to plate via their Screen Trueflow CtP system using Spectra 2 XM screening.

The pages were printed together on a 6-colour Heidelberg 74 B2 press; the paper was Creator Silk 130 gsm. The printed sheets were controlled to ISO 12647/2 using Bodoni PressSIGN software. The printed sheets scored 96% using this software.

 Visually, again the match between the four pages/profiles was perfect. There was little or no loss in gloss for the 220% or 260% TAC profiles when compared with the 300% and 330% TAC profiles.

Also the uncoated Fogra 47 based profiles should, on the basis of these tests, be very useful when using difficult uncoated stocks.

 The use of these types of profiles seems extreme but on the evidence of this trail and VIGC’s own tests it is worth testing  these profiles in your workflow. The gains in press colour stability, ink consumption, ink drying and less marking should be considerable. They are freely avaiable from the the VIGC website.

Links:

http://www.vigc.org

http://w3.efi.com/proofing-and-inkjet-production-solutions/product-overview/efi-colorproof-xf

http://www.epson.co.uk/Printers-and-All-In-Ones/Large-Format/Epson-Stylus-Pro-7900-SpectroProofer

http://www.screeneurope.com/ga_dtp/en

 http://www.bodoni.co.uk/index.php?cPath=205&osCsid=1c39d0032d160af21fdee2c7cfeb49f6

http://www.witherbysonline.com

 http://www.bonhams.com

However many are still concerned that they do not view the images accurately on their computer screens. This makes any judgement of digital images very difficult. [...]]]> When images are required for printed and other media we now all expect that a digital image will be supplied; from a photographer, client, picture library etc.

However many are still concerned that they do not view the images accurately on their computer screens. This makes any judgement of digital images very difficult. We all used to feel very comfortable viewing a transparency on a light box and making critical decisions about it’s use, match to proof etc.

 So now in this digital world the computer screen has to become the digital equivalent of the transparency and light box combined, and trusted in the same way by all involved in the selection and approval processes.

 So how to achieve this? Firstly the computer screen or monitor used must be able to display the number of colours, called a ‘colour gamut’ used by the digital image. Sadly, most of the normal PC screens will not display more then 80 to 85% of the commonly used Abode RGB 1998 profile/gamut used for professional digital photography.

 Happy, there are a number of colour accurate high-end colour monitors that will display between 96 and 98% of this Abode RGB 1998 colour gamut. As you would expect these monitors are more expensive then a standard PC screen purchased from a high street store. But weigh the cost of an extra few hundred pounds needed for these monitors, against the cost of correcting images and media later in the production processes!

 These monitors still need to be ICC profiled, using their own, or third party software, with colorimeters or spectrophotometers to insure their accuracy and use within the computers colour management system.

 But if you are in a colour critical market, these monitors are a small price to pay for viewing, selecting and approving images correctly and accurately. There use is increasing, not just in the professional world of photography, pre-media, publishing and printing. Many brands are using these types of monitors to assure the colour of their images for products and brand colours.