The question often arises whether color profiles should be embedded in the PDF files for proofing.
To answer the question, you have to get some answers: The proof should simulate the subsequent offset printing. For offset printing, with few exceptions, the imagesetters have been configured so that a 70% black in the file is displayed as 70% black on the printing plate, no matter what profile was specified in the file. It didn’t matter whether it was coated paper or uncoated paper: 70% in the file corresponded to 70% on the plate, the choice of the paper printed on resulted in the colour representation.
The proof has also adapted to this: Most proofing service providers ignore embedded profiles, as long as the data is in CMYK and do the same as their print colleagues. Even with grayscale, the profiles are usually ignored and the grayscale is simply assigned to the CMYK black channel. Thus all CMYK and grayscale data are simply interpreted as if they had been created in the output color space. If “ISOCoated V2” is proofed, all images are treated as such, and if “PSOUncoated” is proofed, then the CMYK images are created in this color space.
This is excellent for the majority of files to be proofed. Only RGB colors contained in the data are problematic.
Since the RGB color space is considerably larger than most CMYK color spaces, it must be clear from which color space to convert to CMYK according to which criteria. Most proofing service providers specify a color space from which they convert by default if no RGB color space is defined. This can lead to difficulties: For example, many proof studios choose AdobeRGB as color space because it is large and optimized for offset printing; however, most images from digital cameras come from sRGB and these color spaces differ considerably. Therefore, it is important that the RGB color space and the rendering intend is embedded for a proof, otherwise the proofing software normally selects a color space for conversion to the CMYK color space to be proofed; and this color space is possibly not the one in which the data has be created.
Softproof means: The correct color display of a printed product on a monitor. Both a standardized print, e.g. according to process standard offset printing, can be simulated – e.g. a later offset print according to ISOCoatedV2 can be simulated correctly in colour on the screen – and the output on digital terminals such as LFP systems in advertising technology.
From a technical point of view, soft proofs are now well controllable. The monitor technology is advanced enough to provide excellent displays with a high color gamut and consistent illumination even for a few hundred euros. For example, monitors in two branches of a company can be coordinated in such a way that the result displayed on the monitors corresponds exactly to each other at both locations, i.e. one image editor in Hamburg and one in Munich can talk about retouching the same file.
The problem: The fact that the two monitors emit the identical color and light result can be precisely controlled. The fact that the colleague in Hamburg is looking at the foggy Alster lake at a northern window, while the colleague in Munich moved the monitor to a southern window in the direction of the Isar river in sunshine, already shows the problem: The environment variables under which the softproof is viewed are not identical.
It is even more difficult when the soft proof is to be used in the pressroom to coordinate the production run. Many companies such as JUST offer modern solutions that can provide a soft proof directly at the press. However, the problem remains that the soft proof should be considered to be less than 10% away of the brightness of the press. While 2000 lux brightness was previously the standard for printers, JUST now writes: “The comparison of soft proofs on monitors with prints and hard proofs is regulated in accordance with ISO 12646. The light conditions basically correspond to ISO 3664, but the brightness must be adjusted to the limited luminance of the monitor, which ideally is > 120 cd/m². ”
Two scenarios therefore arise at the printing press: Either the printer is “in the light” and can then match the print with a contract proof printed on paper, or it is “in the dark” and can match the print with the soft proof. The difficulty of matching paper and monitor – and these are two completely different and difficult to compare media – is compounded by the difficulty of the printer having to dim the light at the press by up to a factor of 10 to be able to match both a contract proof and a soft proof at the same workstation. From today’s point of view, this does not really seem practicable.
Conclusion: The soft proof is on the advance and will certainly sooner or later displace the classic contract proof from the market for reasons of speed and cost. However, due to the great technical lighting and haptic differences between the monitor and the illuminated sheet of paper, a widespread introduction is still a long way off. After all, anyone who has ever performed a color match on a printing press can imagine that a match to the contract proof on the one hand and to a soft proof monitor on the other hand is difficult to imagine at the same time. The contract proof will therefore also have to remain the first choice in the near future in order to be able to carry out colour-accurate proofing of the printing result in the pressroom.
Colour is colour, you’d think. That’s right. But have you ever tried to explain the colour of your new car or your new red wallet to a friend on the phone? You will notice that human colour recognition and the reproduction of the same in another medium is very difficult.
The same applies to computers – better: monitors, and printers – i.e.: laser printers, inkjet printers or newspaper printing or offset brochure printing.
Why is the red on a monitor different from exactly the same red printed on paper? It’s simple: put the paper in front of the monitor. The two shades of red are exactly the same. Like this. And now you’re completely darkening the room. What do you see? The red on the monitor is still red. And exactly the same red on paper? This is black now. Why is that? Very simple:
A monitor adds light, i.e. spectral components, to the existing ambient light. If you see red on a monitor, it is because the monitor actively emits red light.
And now the paper: When do you see red on paper? Exactly when white light falls on the paper, for example through a window or a lamp. And when do you see the colour red on paper?
When white light falls on the paper and the paper extracts the non-red spectral components from the white light and reflects the red light. That’s when you see the colour red.
One colour, two completely different ways of production. And this is exactly where the colour calibration and the proof start. The strategy? Fairs. And this under fixed conditions and not with the human eye, but with “incorruptible” technology.
Put simply, a monitor calibration device can measure your monitor and see exactly “how much” colour your monitor can display, and “how wrong” your monitor can display colour. And if your computer knows that, it can correct the monitor.
Another measuring device can emit neutral white light onto a paper and measure the reflected colour. Depending on the printing process and paper, the ink looks completely different, but the meter again sees “how much” ink the print can represent and “how wrong” the print represents ink. And if your computer knows this, it can correct it. And:
If the computer knows the colour representation of the monitor and printer, it can correct and adjust the representation so that both correspond to the same colour. Of course, this only works if the colour and brightness of the light that illuminates the paper is also known and standardized.
And how does the proof work? Very simple:
If a computer also knows that the final printed product is to be printed in offset on an image printing paper, and it knows the colour representation of this printing process, then it can simulate this on a monitor and on an inkjet printer.
On the monitor, this colour-accurate representation is a so-called “soft proof”, the colour-accurate preview of the subsequent print on the inkjet printer is called “Proof” or “Contract Proof”.
This inkjet printing must be very precise and meet the highest demands in gamut and colour simulation. And since the image processing technology, colour matching calculation and measuring technology behind it is not very cheap, proofs are still mostly “expensive” inkjet prints. Due to new printing systems and inexpensive and better measuring technology, however, prices have also fallen significantly here in recent years.
Since 2009 PSOUncoated has been the standard profile for uncoated paper. Nevertheless, proof service providers often have the problem that at first glance proofs on PSOUncoated often differ significantly from the print result. Immediately visible: the white point of the paper.
The PSOUncoated paper white looks very grayish. If, for example, PSOUncoated is proofed on an EFI 9120 XF paper, which actually has a neutral white coloration as paper, then the paper must be recolored by the printer in terms of paper white. This paper-white simulation makes the proof look “grayish” and often not “bright white” like the real production paper. “I can’t put this down to my client” proof service providers often hear from the agencies and designers who commission proofs. And frankly, printing on bright white uncoated paper will also differ significantly from the PSOUncoated Proof result depending on the paper selected.
Some proofing services still proof uncoated paper according to ISOUncoated, because the paper tone is much whiter and not so grayish. In the medium term, however, this will not overcome the misery: PSOUncoated is the current standard according to which the process standard for offset printing certified print shops are also based. But in the pressroom the differences between norm and reality often become apparent. If the new D50 standard light according to ISO 3664:2009 with higher UV components is used for inspection at the printing table, then proof and printing result can often only be matched very poorly. And due to the long standardization periods, this problem will continue to accompany printers and proofing service providers for quite some time to come.
Proofs are standardized products that are created and tested according to a certain set of values. This is exactly the point that distinguishes them from any “colourful printouts”.
Specifically: A proof for coated printing paper is produced according to the standard values of ISOCoated V2 (paper type 1 and 2, glossy and matt coated image printing, dot gain curves A (CMY) and B (K) from ISO 12647-2:2004) and checked according to a set of values (FOGRA39L). A proof for uncoated paper (e.g. PSOUncoated or ISOUncoated) is produced and checked according to completely different value sets. Logically, because a print on uncoated paper looks definitely different in terms of colour and white value than a print on picture printing paper.
A proof must therefore always be prepared according to a standard and be verifiable according to a reference value set. A list of the current Proof Profiles (as of 2012) can be found here.
The problem: Many printing processes such as digital printing on a color laser or printing on a large format printing system (LFP) are not standardized and therefore there are no valid profiles and specifications.
So what to do? The most frequently used standard has established itself as the “de facto basis”: ISOCoated V2.
This is understandable, because colour-critical prints, catalogues etc. are mainly produced in offset printing on picture printing paper and are therefore subject to this standard. It is therefore generally assumed that a digital printer or an LFP printer, for example, should follow this standard and at least achieve this colour result.
So if you need to make a proof but don’t have the exact details of the profile you need, proof ISOCoated V2, which has become the industry’s most widely used standard and will always be accepted as the basic proof.
Unfortunately, a proof without a profile cannot be produced, because that would just be “colored paper from a proofing system”, but not a valid, ISO-compliant proof.
A proof is a standardized product. Take the classic ISOCoatedV2 proof, for example; the standard proof for coated printing paper. Here is the definition in brief:
Metal is printed with a varnish. Neither the colour of the metal of the tin can nor the colour of the lacquer is clearly defined, nor the thickness of the lacquer application and the printing process in which the lacquer is applied (digital print / screen printing, pad printing etc.) is defined.
A contract proof refers to very tight tolerances and precisely defined framework conditions. This includes not only the densitometric and colorimetric reference of the printing ink, but also, for example, the paper white, which is simulated very precisely in the proof. For exactly this reason there is no proof for recycled paper: The papers and paper whites are simply so different that no uniform, standardized “color” of a recycled paper can be defined. From classic recycled paper with a neutral grey or yellowish-grey colouring to de-inked, almost white recycled papers, everything is available on the market. Just not by default.
Therefore, a proof always refers to offset or gravure printing under standardized conditions. Changed surfaces such as metal or changed paper colours such as recycled or high-quality image papers with inclusions or printing on coloured papers have not yet been standardised and therefore cannot be proofed.
There are many possible reasons for a deviation between the proof and, for example, the monitor display:
In general, no patent remedy can be given for the correct display of proofs for the monitor. However, if a proof is provided with UGRA/Fogra media wedge CMYK V3.0 and test report, the chances are high that it reproduces the required colors very precisely. If your monitor image does not correspond to the proof, the error usually lies with you. The list of causes above can help you in troubleshooting.
Especially in larger companies today the layout in RGB is the rule rather than the exception. The advantages are obvious:
In practice, however, there are two potential problems in particular.
Problem 1: CMYK conversion in the last step.
The catalogue is designed in InDesign, all data is perfectly matched, the last step before printing and proofing is the export to a printable PDF in CMYK. Usually this is done via a preset in InDesign, which defines the exact specifications for the color space conversion. In practice, however, this color space transfer can hardly be monitored. The problem: Even if you check the color values in Acrobat in the exported PDF file, for example, Acrobat does not really display the colors it contains. Acrobat brav would show you CMYK values even if the RGB images are still wrongly contained. However, other CMYK values can occur during printing when the data is processed again. Lately it looked like this:
For some years now, the possibilities of colorimetric measurement of printing inks have become simpler and cheaper. And so it is often believed that measuring printing inks is simple, inexpensive and, above all, highly accurate. And this also across a wide variety of brands and generations of measuring devices. Is that true?
If you look at a few studies, that does not necessarily seem to be the case. IFRA, for example, requires that when measuring BCRA ceramic tiles the colour differences between different measuring instruments should be below Delta-E 0.3. In reality, however, things looked different. In a Nussbaum study, 8 out of 9 measurements were for a Delta-E greater than 2.0; in a Wyble & Rich study, the deviations were between Delta-E 0.76 and 1.68. But why are the deviations so large?
On the one hand, the measuring instruments differ in the way they illuminate the surfaces to be measured. This is important in two respects: On the one hand, measurements can vary greatly depending on the material, for example, because light is emitted and measured from only one light source onto the measuring surface. If a measuring instrument has only one lamp, which, for example, radiates at an angle of 45 degrees onto the measuring surface and whose reflection is measured, then the measurement can deviate by up to Delta-E 3.0 if you only rotate the measuring instrument about its own axis. If a left-handed person and a right-handed person measure the same tiles with the same measuring device, then just by holding the measuring device differently and by the different lighting angles of the tiles a measurement can be completely different.
The solution for this: In a measuring device, several light sources are distributed or, in the best case, the illumination is emitted directly circular at an angle of 45 degrees in order to minimize such effects.
Important innovations of the reformed ISO 12647 will be:
Why is ISO 12647 being revised? Environmental conditions have changed significantly at three central points since the last revision in 2004.
The previous paper types 3 and 5 with the paper whites defined in 2004 are hardly available on the market today. Even picture printing papers today show a much stronger blue colouration than just a few years ago. In addition, the revision of D50 in 2009 means that the lighting in the pressrooms now also contains considerably more UV than before 2009, which has caused problems in the matching of proofs without optical brighteners compared to papers with a high proportion of brighteners. Instead of the previous 5 paper types, there will probably now be 8 new paper types which also differentiate between glossy and matte picture printing paper:
Based on these eight types of paper, a total of 16 printing conditions are created by using frequency modulated non-periodic screening and conventional periodic screening.
The ISO 12647-7 proofing standard was revised in November 2016 and the test criteria for FograCert contract proof creation were adapted. We have now incorporated these changed criteria into our proofing system and are now working to the stricter tolerances of the latest ISO 12647-7:2016.
The good news is: you won’t notice that our proofs are now precisely produced according to the latest standards. Why? Quite simply: Because our demands on our proofing system, our FIERY proofing software, our EFI proofing papers and the X-Rite measuring decvices are already so high that all components of our proofing system – and of course our proofs themselves – have been meeting the new criteria of the revised November 2016 standard for years.
The new standard brings the classical formula for the colour distance Delta-E from the traditional definition of 1976 (CIELAB 1976) to the updated version of 2000 (CIEDE2000). Since the values cannot be converted directly, new tolerances for the test report are introduced, which are valid immediately. These new tolerances and new criteria are also the only difference that you will notice on our proof when you take a closer look at it.
Why this change: Fogra used measurements from the 116 Contract Proof Certifications from 2016 to show that the old and new tolerances of the old? These colors have so far had a? E-value that is too high in relation to the visual assessment. The new Delta-E values, on the other hand, are much more “equidistant”, i. e. with the human assessment of the colour distance, which Fogra has also demonstrated in tests.
The deviations of the gray axis and hue are now also determined more precisely, the evaluation of the hue spacing? You can also see this on the test report. The Fogra writes:”Since HC mainly depends on the hue angle, the evaluation of neutral grey or similar colours with sometimes very large differences in brightness and saturation did not yield meaningful results. The measure?Ch now describes the actual distance of a color pair in the CIEa*b* plane and is therefore no longer suitable only for the evaluation of the colorfulness difference of very rich colors.
The ageing tests for proof papers were clarified more clearly with the introduction of the new standard. All certified proof papers undergo the following tests: (more…)
Current proofing systems can reproduce spot colours like HKS or Pantone very well. Using the Fiery XF 6.3 proofing software and the Epson SC-P9000V proof printer, we evaluated with which colour deviation in Delta-E the PANTONE Extended Gamut Coated colours can be proofed.
The colour deviations were calculated by the proofing software on the basis of the measured colour space of the proofing system of proof.de. Therefore in practice there may be deviations. However, it has been shown that almost all PANTONE colours can be simulated quite well in the large colour space of the proofing device.
The smaller the ∆E value, the smaller the colour distance from the PANTONE reference to the proofed PANTONE colour. Higher ∆E values indicate which PANTONE colours can be reproduced in the proof with greater difficulty.
|Delta-E Colour Deviation
Colour Deviation Proof
|PANTONE 100 XGC||0.24 ∆E||PANTONE 355 XGC||0.84 ∆E|
|PANTONE 101 XGC||0.24 ∆E||PANTONE 356 XGC||0.00 ∆E|
|PANTONE 102 XGC||0.49 ∆E||PANTONE 357 XGC||0.64 ∆E|
|PANTONE 103 XGC||0.64 ∆E||PANTONE 358 XGC||0.27 ∆E|
|PANTONE 104 XGC||0.93 ∆E||PANTONE 359 XGC||0.27 ∆E|
|PANTONE 105 XGC||0.77 ∆E||PANTONE 360 XGC||0.59 ∆E|
|PANTONE 106 XGC||0.24 ∆E||PANTONE 361 XGC||0.65 ∆E|
|PANTONE 107 XGC||0.50 ∆E||PANTONE 362 XGC||0.35 ∆E|
|PANTONE 108 XGC||0.25 ∆E||PANTONE 363 XGC||0.38 ∆E|
|PANTONE 109 XGC||0.26 ∆E||PANTONE 364 XGC||0.88 ∆E|
|PANTONE 110 XGC||0.57 ∆E||PANTONE 365 XGC||0.26 ∆E|
|PANTONE 111 XGC||0.98 ∆E||PANTONE 366 XGC||0.27 ∆E|
|PANTONE 112 XGC||0.36 ∆E||PANTONE 367 XGC||0.55 ∆E|
|PANTONE 113 XGC||0.25 ∆E||PANTONE 368 XGC||0.61 ∆E|
|PANTONE 114 XGC||0.50 ∆E||PANTONE 369 XGC||1.04 ∆E|
|PANTONE 115 XGC||0.50 ∆E||PANTONE 370 XGC||0.00 ∆E (more…)|
PANTONE has done it again: Following the changes from 2010 to 2014, PANTONE is now expanding its Solid Coated and Solid Uncoated palette with 112 new colours. For users of the current Solid Plus Series, PANTONE is offering a fan with the new colours in Coated and Uncoated as an extension for 30 Euros. And of course PANTONE also offers updated Solid Coated and Solid Uncoated and Bridget fans … and of course an updated version of all associated libraries.
The reason for the 112 new colours is not entirely clear. PANTONE writes vaguely, “112 industry-desired and inspiring spot colours to complement our existing collection” and “The 112 new spot colours are market-relevant, focusing on specific desired colour ranges that offer designers the most advanced and inspiring colour options for creative design application, expression, communication and specification.”
Let’s be honest: Positively phrased, this does not sound like a convincing colourimetric concept. So it is not surprising that on the American website there is a dazzling image film with designers who really wanted these colours. Due to a lack of relevance this film was probably not even offered in German …
Still, the new colours are here, and designers, graphic artists and printers are called upon to deal with them. The libraries in the PANTONE Color Manager are already updated, and the colours are also available online in PANTONE.
At the moment we do not have the colours available in LAB via FIERY in the system, but due to the published colour values we can proof the colours in sRGB or CMYK variants. We have already completed a first order – so the colours seem to be not completely irrelevant for the industry after all.
The WAN-IFRA Standard Profile for newsprint “ISOnewspaper26v4.icc” is contained in countless newspaper printing specifications around the world, almost every German newspaper is printing to this proven standard.
Now the IFRA has placed a successor with the new ISO Newspaper 26v5 to the starting line, that increasingly conquers market shares. The new profile adapts the changes in ISO 12647-3: 2013, in particular with a decreased total ink coverage. The current ICC Profill called ISOnewspaper26v5.icc contains a total ink coverage of 220% and a dot gain of 26%. The name of the new profile is “WAN IFRAnewspaper26v5.icc”. The new newspaper printing profileWAN-IFRAnewspaper26v5 Proof Profil available.
Since today we offer proofs in ISONewspaper26v5.
No further documentation was available at that point on the IDEAlliance Website. The ICC files can be downloaded in a ZIP file here:
Following today’s kick-off of the new Fogra 51 (PSO Coated V3) and Fogra 52 (PSO Uncoated V3) printing conditions, Fogra and ECI (European Color Initiative) have published the new profiles and associated characterisation data on their respective websites.
In each download you will also find PDF files with explanations and notes on the respective profiles and characterisation data. On the Fogra page you will also find the current colour values for the UGRA/Fogra Media Wedges CMYK 3.0 for the new printing conditions PSO Coated V3 and PSO Uncoated V3.
Nowadays, two different processes are used in web offset printing: heatset and coldset.
The coldset process is mostly used to print newspapers and paperbacks, with the printing ink drying purely by absorption.
In the heatset process, the paper is passed through a large dryer and a chill roll unit after the last printing unit. The length of the printing press is almost doubled by these two units. To ensure that the ink dries optimally, special heat-drying inks are used here.
Current proofing systems can print spot colours like Pantone or HKS very accurate. With Fiery XF 5.2 Proof software and the Epson 7900/9900 proof printers we evaluated, with which colour deviation PANTONE Solid Coated and PANTONE Solid Uncoated colours can be reproduced in proofing.
The colour deviations were calculated based on the measured colour space of the proof system of Proof GmbH by the proofing software. Deviations should therefore be quite similar in practice. Almost all PANTONE colours can be simulated quite well in the wide colour gamut of the proofer.
The smaller the Delta-E value, the lower is the colour distance of the PANTONE reference to the proofed PANTONE colour. Higher Delta-E values show, which PANTONE colours can’t be simulated accurately in the proof.
|Farbabweichung im Proof in
|Farbabweichung im Proof in
|PANTONE 100 C||0.89 ∆E||PANTONE 100 U||1.69 ∆E|
|PANTONE 101 C||0.60 ∆E||PANTONE 101 U||1.62 ∆E|
|PANTONE 102 C||1.23 ∆E||PANTONE 102 U||1.40 ∆E|
|PANTONE 103 C||0.72 ∆E||PANTONE 103 U||0.49 ∆E|
|PANTONE 104 C||0.48 ∆E||PANTONE 104 U||0.92 ∆E|
|PANTONE 105 C||0.80 ∆E||PANTONE 105 U||1.07 ∆E (more…)|
The Proof GmbH has thus reaffirmed it’s quality by the strict criteria of Fogra. The tests Fogra conducted went far beyond the pure colorimetric readout of a media wedge. The special proofs for Fogra were evaluated among the following criteria:
The color matching our proofs submitted for the test was confirmed by Fogra with date of September 24, 2015. The Proof GmbH is thus the world’s first company that has certification for the production of contract proofs on a Fogra 51 and Fogra 52.
We are very pleased that our preparation and the efforts of the past few months were rewarded by a successful certification. You can order Fogra51/52 proofs in our proofing shop Order Fogra 51 / Fogra 52 Proofs (PSOCoatedV3 and PSOUncoatedV3).
The full, 12-page report from Fogra can be downloaded here:
Fogra certification report on Proof GmbH of 2015 No. 29712
It is actually quite simple to have proofs made. But experience shows that many customers often stumble over the same mistakes. We have put together the ten most important steps towards a successful proofing job:
In the following we would like to present these individual points in more detail.