Different surfaces can influence both the colour and the appearance of objects. A colourful and glossy object will usually appear more saturated to the eye, while a similar object with a matte, diffuse surface will appear duller.
If you form a glossy, a semi-matte and a matte surface from the same black plastic, the glossy surface will often appear blackest, while the very matte surface will appear much lighter. The same effect can be reproduced with film lamination of prints: a glossy laminated dark blue or black appears more saturated and darker, a matt laminated black becomes lighter and greyer to the human eye due to diffuse light refraction.
Humans perceive the colour of objects through the light reflected from them, and different surfaces reflect light differently. In general, therefore, there are two ways in which light is reflected from an object: The specular and the diffuse reflection.
Specular reflection occurs when light is reflected from the light source at an equal but opposite angle. Simply put, you can think of it as a ball bouncing off a smooth floor and bouncing back at the same angle. This reflection occurs mainly on objects with shiny, smooth surfaces.
If, on the other hand, the reflected light is scattered in numerous different directions, we speak of diffuse reflection. This reflection occurs on objects with matt and irregular surfaces. A ball would bounce off such a surface – for example, an irregular floor consisting of numerous pyramids of different sizes – sometimes at one angle and sometimes at a completely different angle.
Today, when colour and gloss are to be evaluated in global supply chains and on different surfaces, this is often done with sphere head spectrophotometers such as the KonicaMinolta CM-26d, with which we at Proof GmbH have also measured the semi-matt and matt free-colour CIELAB HLC Colour Alas XL. With the d:8° geometry and the integrated 60° gloss sensor, which can handle both the SCI – “Specular Component Included” and SCE – “Specular Component Excluded” measuring modes, this measuring device can measure colour and gloss within less than a second without having to use an additional measuring device for gloss and always having to be set up and aligned again.
With integrating sphere measuring instruments, the surfaces to be measured are usually illuminated at all angles and measured at an angle of 8 degrees from the vertical axis. This measurement condition is referred to as d/8 or d:8. Most of the integrating sphere measuring devices such as the CM-26d can measure with or without a gloss component as previously described.
In contrast, the 45/0 models used in the printing industry such as the X-Rite i1 Pro2 always measure without the specular reflection. The reflection of the sample surface is therefore perceived differently by the optical geometries d:8 with gloss component – SCI – , d:8 without gloss component – SCE – and 45/0 respectively.
To measure the true colour of an object without the influence of surface texture, the Specular Component Included (SCI) measurement mode is used. SCI mode includes both specular and diffuse reflected light and is ideal for quality control and colour quality monitoring.
The Specular Component Excluded (SCE) measurement mode, on the other hand, which excludes specularly reflected light, is used to evaluate the colour of an object to match the visual perception of the human eye. In SCE mode, a glossy surface is typically measured darker than a matte surface of the same colour; similar to how the human eye sees it. This mode is typically used in quality control testing to ensure that colour matches colour standards through visual inspection.
For whatever reason: December is traditionally the month in which we make the most important new acquisitions. In order not to break with this tradition, the new proof printer generation from EPSON moved in with us this year: The SureColor SC-P9500 Spectroproofer.
Unpacking traditionally has to be done in front of the door, we wouldn’t be able to get the printer into the office on the two-metre-long pallet, but once it’s on rollers, it works fine.
The new SureColor P9500 complements our range of SureColor 7000 and 9000 proof printers and, above all, hopefully brings us a further plus in speed, especially for larger jobs. Thanks to a newly developed and now fully loaded print head with 12 inks with up to 800 nozzles each, it is said to print up to 2.4 times faster than our other proof printers, which is particularly advantageous for large proof volumes.
We are currently still in the process of measuring the large number of media we use on the new printer and gaining experience with the new proof printer. Many of the “advantages” are not really relevant for us, as we have very specific requirements in proof printing. In terms of gamut, i.e. the maximum colour space that can be achieved, we were unfortunately unable to determine any real gain. According to our measurements, the colour space has changed marginally compared to the previous proof printers, but not really increased.
For example: Admittedly, the printer prints much faster than our other printers. But in return, it takes much longer to transport the proof paper to the fans for drying, and the subsequent measurement of the media wedge also takes longer than on the 7000 and 9000 systems. For an A4 proof with media wedge and test report, the 9500 is only 8 seconds faster, taking just over 8 minutes. In other words, the higher print speed is almost completely lost in other areas.
Therefore, A4 proofs will not be the domain of this printer, but rather we will try to proof the larger formats on the 9500, where the speed advantage comes into play more.
This reminds me a little of the upgrade to Fiery 7, which was supposed to be up to 5 times faster than the previous version with FastRIP technology. In fact, the FastRIP technology was and is so error-prone that we were never able to use it, as we felt that every 20th job was processed incorrectly or could not be processed at all. On the other hand, with the version upgrade, the entire proofing software became considerably slower … So for us as non-FastRIP users, all that was left on average was a slower system.
And so we are still making our experiences with the new proof printer. The first conclusion we can draw is that many things are better, some are worse and some are simply different. The fact that the printer is still quite new is also evident from the fact that new media updates are constantly being added. We have already run some good jobs through the printer and it has not disappointed us. In this respect, the first conclusion looks fairly optimistic.
The "ISO/IEC 15416:2016 - Information technology - Automatic identification and data capture methods - Test specifications for bar code print quality - Linear symbols" specifies the current criteria for testing bar codes. ISO 15416:2016 replaces ISO 15416:2000 and defines modified bar code quality calculations for some areas. During the barcode check by Proof GmbH, barcodes are checked according to the current criteria of ISO 15416:2016.
Recently we received a PDF file from a Swiss customer who asked us to proof it according to ISOCoatedV2. The format was PDFX-4, we could open the file, preflight it and also display it in Acrobat. However, when proofing in Fiery XF 5.2, the file was only output after a RIP time of over 3 hours. Adobe PDF X4 screen output in Acrobat Professional We have recorded the screen layout on a modern Macbook Pro with four processor cores and the latest Acrobat Pro version to illustrate the enormous demands on computing power. It was clear from the screen layout that the RIP time would be quite long, but three hours with just one use was quite unusual, especially since in our RIP two instances of the Adobe PDF Print Engine work simultaneously. Where exactly the error lies in the extremely high RIP time is not yet clear. Both EFI, as the manufacturer of the Fiery RIPS, and Adobe, as the manufacturer of the PDF Print Engine (APPE), have been given the information that on a Harlequin RIP the file was probably ripped within a few minutes. So a bug in the Adobe PDF Print Engine might also be a reason for the long processing time. It' s a typical problem. From creation programs such as InDesign and Illustrator, the flattening of file elements with X/4 is passed on to the RIP in the print shop or proof printer. The case in question was calculated on a quad-core system with SSDs with two instances of the Adobe PDF Print Engine and output correctly for three hours 47 minutes. However, since the final product cover is not expected to be produced in Europe, but in Asia, it was decided to break down the complex graphics with transparencies, drop shadows, etc. in Photoshop and then reuse it as a transparent PSD file. The resulting PDF X/3 file was ripped and proofed within seconds. The colour result was identical to the X4 file. This example shows: PDF X4 is not just a modified data format. It also shifts the computing power and software requirements from the data creator to the data processor or printing house. But especially with complex graphics this can lead to unpredictable effects. Although PDF X/4-capable solutions such as Fiery XF 5.2 do exist today, a RIP time of over three hours is of course not practical.
With the new SpectroProofer ILS30 made by X-Rite, Proof GmbH has created the basis for automated measurements and Proof verifications according to M1 standard. Proofs with optical brighteners (OBAs - Optical Brightning Agents) can now be measured. Contrary to earlier announcements, the new SpectroProofer are also able to measure the current proofing standards as before in M0 measurement standard. Because of the new ILS30 SpectroProofer, the layout of the Ugra / Fogra media wedge was slightly modified. For a comparison between old and new media wedge, see the image below. (more…)
Since many printed matter contains spot colours such as Pantone or HKS, the question often arises whether these colours can be proofed at all. The answer is "no". Only an approximate simulation of these colors is possible. The reason: Each special ink is a specially mixed, "real" ink and therefore cannot be mixed from the 4 printing inks (cyan, magenta, yellow and black). Today, modern proofing machines have up to 12 different printing colours and, in addition to the classic primary colours, also have, for example, orange and green and violet as real colour pigments in the machine. Proof printers such as the Epson SureColor P9000V are therefore capable of displaying significantly larger color spaces than, for example, ISOCoatedV2. The spot color simulation in these devices is therefore sometimes very good when controlled via a Contone driver, which can access the entire color space of the proof printer. Epson himself points out, for example, that "98% of all Pantone colors" can be covered. This may be doubted, but a number of over 90% of all Pantone colors is realistic from our point of view. In the past, Pantone and HKS colors were simply converted by the proofing systems to CMYK and then simulated in the standard color space, i.e. mostly ISOCoatedV2. The representation of the colors here is mostly completely insufficient. For the reproduction of Pantone and HKS colours in a proof it is therefore immensely important to have a modern proof printer with many colours and a high colour gamut and a modern proofing software which is also able to precisely control the printed gamut. Differences in the quality of the simulation of spot colors can quickly be seen in the different printing systems: If the proofing service provider prints with an older 6-color or 8-color system (Cyan, Light Cyan, Magenta, Light Magenta, Yellow and Black or Light Black), spot colors are simulated worse than, for example, with a modern 11-color system with Cyan, Light Cyan, Orange, Yellow, Magenta, Light Magenta, Photo Black, Matte Black, Light Black, Light light Black and Green. The higher simulation quality of the spot colors is generated by the fact that orange, for example, already exists as a separate color and does not have to be mixed from magenta and yellow before the spot color simulation. Of course, it must be said that there are limits, especially in the area of metallic or fluorescent colours; these colours are currently not reproducible in proofing. The spot-colour simulation of gradations is also critical In most proofing systems, only the 100% values of a Pantone or HKS color are underlaid. If, for example, a font logo with 100% color application of a Pantone color is to be simulated, this is precise and is well represented in most proofing systems. However, it becomes more difficult if the logo contains not only 100% areas but also a 30% Pantone colour area, since this is not defined in the proofing system, but is simulated by the proofing system. In some cases, considerable deviations from e.g. HKS colour fans can be observed. It becomes even more difficult if, for example, a grayscale TIFF lies on a 100% HKS area and overprints. For the graphic professional it is immediately comprehensible that the HKS surface simply has to become correspondingly darker at this point due to an overprinting 30% black. However, the proofing software must recognize this effect correctly, calculate it correctly and then simulate it correctly with the 11 colors available from the proof printer. It is easy to understand that countless errors can occur. And the supreme discipline: 7-colour Pantone files with lots of overlaying and overprinting Pantone colours or HKS colours with overprinting CMYK elements can at best be calculated even by the most modern proofing systems, but can by no means be colour-accurately simulated. The bad news is that a proof with spot colors is therefore never as color-binding according to the current state of the art and varies more depending on the proofing system. But the good news is that spot colors, especially solid colors, can now be simulated well by modern proofing systems. A modern proofing system therefore also offers the possibility of getting a realistic impression of spot color prints at a fraction of the cost of a test print on a offset press.
Epson has incorporated many improvements into the new printer generation. For example, fully loaded print heads now work in the new printers, which can finally handle photo black, matt black and the two grey tones LightGray and LightLightGray as well as the colours orange, green and violet simultaneously in one print head. For cyan and magenta there are also the light variants light-cyan and light-magenta, so that besides yellow, cyan and magenta, 12 full colours are available in the print head. The printer uses the new UltraChrome Pro12 ink set, which could possibly bring some detail improvements to the classic K3 inks, although nothing more is known about this yet.
A proof is one that is produced according to the specifications of the latest revision of the proofing standard ISO 12467-7 and is within the tolerances of this standard. The current revision is ISO 12647-7:2016, which has been tightened even further with this standard and has been supplemented by a certified edition of spot colours such as PANTONE and HKS.
But what makes the certified proof cheap? That's the low price. Proofs are printed on certified proof papers on very high-quality pigment inkjet printers, usually using expensive proofing software, and measured with spectrophotometers. So how can production be done cheaply here?
One litre of ink for proofing devices is around 400 EUR, so it makes sense to use inexpensive alternative ink from China. The problem: there are no manufacturers - neither in China nor anywhere else - who produce inks that would actually produce similar inks in terms of pigment colour and spectral composition. I once called a manufacturer who advertises that his - already quite expensive - inks could also be used for proofing. When I asked him, he said: "No, no, that's just for advertising, but of course I would never do that or recommend it, and I don't know anybody who does that. As for the China inks, he said: "They start at 20 EUR per liter, but you get a different ink with every delivery, depending on where the wholesaler buys. Then they have to re-measure the proofer every time… forget it." In addition, replacing a clogged print head costs around 2,500 EUR, so the risk is too high. A real proof therefore only works with original, very expensive ink.
GMG ColorProof, EFI Fiery XF and ORIS Color Tuner are just some of the most important proofing solutions on the market. What they all have in common is that proofing software is rather a niche software, so the programming effort is very high compared to the sales figures. Depending on the size of the output device and the range of functions in terms of verification, spot colour display or proofing on special materials such as transparent foils, etc., the software costs between 5,000 and 10,000 EUR, and in combination with other software products from GMG or Colorlogic it can quickly cost considerably more. Although there are a few low-cost solutions here too, these are usually irrelevant in professional proofing, as they are either not suitable for more than one workstation, or important functions such as spot colour libraries etc. are missing.
With DieDruckerei.de, the first well-known online printer has switched to PSOCoatedV3 and PSOUncoatedV3. A sign that almost exactly three years after the new Fogra51/52 standards appeared, they are increasingly being used in production and as a requirement for printers to produce data. The fact that also here the conversion does not run completely smoothly, shows up in the data requirements, which recognize beside the new PSOCoatedV3 also a 300% variant of the profile - a legacy from the ISOCoatedV2 300% times, PSOCoatedV3 is present only in a 300% version, a profile PSOCoatedV3 300% does not exist therefore. Nevertheless, the conversion shows that the new Fogra 51 and Fogra 52 profiles are also increasingly being used in online printing. A replacement of ISOCoatedV2 is still a long way off, the profile is simply too successfully anchored in the market and also well established as a defacto master standard for numerous printing processes in digital printing, trade fair construction, flexo printing and much more, so that this will take several more years. But with every major player in the printing market that advocates the conversion, the spread will increase and the new profiles will also be used in prepress.
It has taken almost a year, but we are all the more pleased now: The "CIELAB HLC Colour Atlas" is completed and can be ordered in our shop. The HLC Colour Atlas is a open source, high-precision colour system based on open standards. The CIELAB HLC Colour Atlas offers professional users of colour three decisive advantages:
Every print shop in Germany adheres to a predefined standard, the process standard offset printing. This standard defines target and tolerance values for printed products. In order to prove that your proof delivered to the print shop meets these standards or is within the tolerances, the media wedge is measured and the values analysed in case of doubt - i.e. in case of a streak. If these measured values are correct, the print shop is obliged to adhere to and achieve these values. Practice generally shows the following: If you want to have a 4-page image brochure proofed and printed, it is usually sufficient to have a single media wedge printed under the 4 pages. If the media wedge is also provided with a test report, the colour accuracy for the print shop is directly confirmed as a guideline. However, if you want to be on the safe side, have a separate media wedge (including test report) printed under each of the 4 pages of your brochure.
A proof is only as good as the light under which it is viewed. Just going to the window or switching on the light at dusk is useless: between December and July, between 8 am and 8 pm, between cloudy and sunny days there is a huge difference in the lighting, which makes any colour evaluation impossible. And if you switch on the light, you normally switch on a bulb with 2700 Kelvin - or even worse: an energy-saving neon bulb that somehow shines in any spectra... a disaster! The reasons for metamerism effects (in short: that two colors look identical under one light, but completely different under another) lie in the different printing technologies. Colors that look the same under a light bulb can suddenly look very different under a neon tube. In recent years, ink-based digital proofs have established themselves in the proofing sector. Because it is printed in ink, specially coated paper must be used, which is not in any way similar to the subsequent production run. Anyone who has ever tried to print on glossy coated paper with an inkjet printer knows: the ink never lasts! Metamerism is therefore always involved when a proof is to be compared with offset printing. The light under which proof and production run are viewed is particularly important. ISO 3664 regulates standardized light, which is important for viewing proofs and prints. D50 is no longer D50: The International Lighting Commission CIE has revised ISO 3664 in recent years and adapted it to today's circumstances. If UV components used to be strictly prohibited, they are now part of the standard. In the past, the focus was on consistency between slide and print, while today monitor, digital proof and offset printing are important. Therefore, proofs must always be viewed under D50 Standardized Light, so that they are really "colour-binding" in their perception. If you want to check metamerism effects, we recommend the UGRA colour temperature indicator. With these strips, metamerism effects can be checked very quickly and clearly.
freeColor e. V. is a consortium of German and Swiss color experts who work to produce consistent color in all areas of application. Sounds reasonable? Exactly. That is the issue that is of central importance to our proofing customers. Therefore we are currently working in a project with the colleagues of FreieFarbe e. V. and are now also as Proof GmbH member and partner of FreieFarbe e. V. FreeColor relies on open standards such as LAB and HLC, which have long been integrated in computer software and want to show: the computer is an ideal tool for color, it can make color free! The association FreieFarbe e. V. aims to promote colour communication without pursuing commercial goals. freeColor e. V. would like to promote developments that...
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.
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.
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.
PANTONE EXTENDED GAMUT Coated
|Delta-E Colour Deviation Proof||
PANTONE EXTENDED GAMUT Coated
|Delta E 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…)|
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. (more…)
Proof GmbH has again been certified by Fogra in September 2015, this time for the standards Fogra 51 (PSOCoated_v3), Fogra 52 (PSOuncoated_v3) and Fogra 39 (ISOcoatedv2). 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: