A very frequent topic for us in the area of proofing is the optimal conversion of PANTONE colours in CMYK for classic, inexpensive four-colour printing. In the last few days, there has been a lively discussion on this topic in the Adobe Forum and in the colour management forum of hilfdirselbst.ch, which I would like to summarise briefly, as our customers often struggle with the same issues.
The central question is to which standard or colour profile a CMYK value of a PANTONE colour in Bridge actually refers. Specifically, a user asked for the conversion of PANTONE 116 C, a colour tone that is specified in the PANTONE Bridge fan in CMYK 0/14/100/0 (here you can see the original value in PANTONE). But if you now convert the underlying PANTONE Lab color value in InDesign or Photoshop into different CMYK profiles, you will get different, significantly different color values. “What does the PANTONE Bridge CMYK colour value refer to” was the original question of the discussion.
But one thing is clear: without precise information on the substrate, print density, inks used, etc., the information provided there has only limited validity. If, for example, one converts the LAB colour value of PANTONE 116 C into the SWOP Web coated commonly used in the USA, then one reaches a value of 20 in magenta instead of 14 as indicated in the PANTONE Bridge Fan.
If you compare the original PANTONE LAB values and the PANTONE Bridge CMYK values in European standards such as ISOCoatedV2 or PSOCoatedV3 for coated or PSOUncoated or PSOUncoatedV3 for uncoated paper, there are sometimes serious colour deviations. The PANTONE Cool Gray 2 is much too light in CMYK conversion, the PANTONE Cool Gray 11 is always much too dark. For the PANTONE 3278 C, the Bridge CMYK value for PSOCoatedV3 fits quite well, but the same comparison for Uncoated is noticeably worse. What is the reason for this?
One thing is clear: there are no system errors. PANTONE knows what they do. But it is surprising that the bridge values have apparently been fluctuating by several percentage points for many years. Perhaps one reason for this is that different base pigments have been used over the years and the values have therefore been adjusted. But it was not possible in any way to find out how the values are created, what profiles or logic could be behind the values. Some discussion participants thought of a deliberate system error: “Cui bono? Why should a spot colour manufacturer deliver perfect CMYK replacement values for his products? That would be detrimental to business.”
This is an exciting approach which, at second glance at the latest, does not lack a certain logic. If the head of the company has only seen bad CMYK conversions of his PANTONE spot colour for long enough, he will sigh and agree to any surcharge for a five-colour print, only to finally find his corporate colour correctly reproduced again.
But another thesis is also very plausible:
Let’s assume that a PANTONE “Green1” corresponds colorimetrically to a CMYK of 30/0/100/0. If two more saturated green tones (“Green2” and “Green3”) are displayed in the fan, which theoretically should be displayed with CMYK 35/0/110/0 and CMYK 40/0/120/0, what then?
To set all three green tones to CMYK 30/0/100/0, i.e. the next CMYK value that can be achieved absolutely colorimetrically? That would actually be the most obvious way, especially since it is very unlikely in practice that two adjacent PANTONE colours would ever be used in CMYK conversions. Because a company has either green1 or green2 as its corporate colour, but hardly both at the same time.
On the other hand, buyers of PANTONE Bridge fans would probably be very surprised if different PANTONE colours in the fan had the same CMYK value.
Therefore, a psychological-sales-department correction is obvious: In order to avoid identical CMYK values, we set the most saturated green tone to the not matching CMYK 30/0/100/0, and then the less saturated colors to 25/0/0/90/0 and 20/0/0/80/0, i.e. also not matching CMYK values. Now nothing fits anymore, but at least all colors have different CMYK values.
Practice shows: An adjusted conversion via ICC profiles often provides a better CMYK color value for the conversion of PANTONE colors like the CMYK value from the PANTONE Bridge.
We have converted the PANTONE colours used in the above mentioned graphics also via ICC profiles partly absolutely colorimetrically and relatively colorimetrically with depth compensation (marked with an “r” behind the CMYK colour value) into the two output colour spaces PSOCoatedV3 and PSOUncoatedV3 and have mapped the visually best match in each case.
In most cases, this conversion adapted to the output color space delivers the significantly better results. See for yourself:
If you need the best possible conversion of one or more PANTONE colours to CMYK, we will be happy to support you with our know-how and our measuring and proofing technology. We determine and compare different imaging variants of a PANTONE colour in CMYK and show you the best determined conversions in CMYK with metrological evaluations in Delta-E00.
We have added 140 additional paper white values from Arctic Paper, Peyer, Igepa, Antalis and Mondi. As a result, a total of almost 1400 paper whites are now available in our database.
From the company Peyer we have added the colour shades of the Surbalin product range, although we have not covered all surfaces individually here. However, we have now also included other Peyer products such as Peytan, Peydur, Peyprint and Comet in the paper white database.
You can find the paper white database at shop.proof.de:
Today a customer called who wanted to order a proof of several HKS N spot colours on an uncoated paper. “Which proof profile should I choose? And how exactly can you match my special colours in the proof? I probably have to proof several HKS N red tones in comparison. By the way, the printing is to be done on Fly Cream, a slightly yellowish paper.”
First of all, I searched with the customer for the production paper in our paper white database. A quick look via full text search revealed that we have measured Fly Cream from Papier Union:
With a B-value in LAB of 9.2, Fly Cream is really not just a little yellowish, as the customer said, but clearly yellowish, chamois, creamy … whatever you want to call it. So it was natural to check the proof profile “ISOUncoatedYellowish”, Fogra 30, to see to what extent the paper white could match.
Together with the customer we looked up our “paper white of proof profiles” table:
Contrary to the customer’s expectations, the paper white of ISOUncoatedYellowish is not even as yellowish as the paper white of the edition paper Fly cream, which is more yellowish by more than 5 steps on the B axis. So it was clear: PSOUncoated as a brighter-free uncoated paper proof standard is clearly too white, ISOUncoatedYellowish is much more suitable.
As is well known, elections are always around the corner, and the trend towards ever larger and more numerous election posters is unbroken. In the past, only Mother Nature made the landscapes colourful in spring, but today every local, state, federal and European election does so easily. Every candidate, every large or small party now has the technical and financial means to transform entire streets into a colourful sea of messages and faces. Once the photographer has captured the election candidates well in the studio, the pictures go off for retouching and then for layout.
Until a few years ago, election posters were usually produced in classic offset printing and then glued onto hardboard with paste, drilled or screwed onto roof batten stands and then attached to street lamps with wire. And if the election took place in the summer, the posters were printed in a double edition, so that in an emergency the faded prints could be pasted over and refreshed with new ones after one month for the final spurt.
Today, however, the corrugated plastic poster is becoming more and more popular, as it is supplied pre-drilled and ready to use, retains its colour for several months and can be attached to street lamps with cable ties. But how should print data be created and how should data be prepared and proofed?
Corrugated plastic posters are produced on different systems. Sometimes four colours are used, sometimes six, sometimes more colours. Therefore, there are no binding proof standards for most digital print products produced in this way.
Instead, it works the other way around: Since most of these digital printing systems have at least the colour gamut of offset printing on picture printing paper, these printing systems are based on the established colour gamut of ISOCoatedV2.
For example, Printpartner-XXL writes: “For colour-critical motifs, we therefore recommend a prepress proof on the original material or the delivery of a colour-binding proof (with media wedge and date). Data that is delivered without colour information is provided and produced with the standard profile “ISO Coated v2”. In such a case, a colour complaint cannot be accepted.
Eine Reklamation der Farbe kann in so einem Fall nicht anerkannt werden.
From our point of view, most printing specialists demand ISOCoatedV2, some like flyeralarm and wir-machen-druck ISOCoatedV2 300%. Some want black exclusively as pure black, some exclusively as CMYK 50/50/50/100 colour black … and some do not give any information about the required colour profiles … but if you don’t specify anything, you probably won’t stick to anything … so if you want to be on the safe side, you should choose a supplier with a functioning colour management system and specifications for colour profiles.
Current proofing systems can reproduce spot colours such as HKS or Pantone very well. With the Fiery XF 6.5.2 proofing software and the Epson SureColor-P9000V Spectro proof printer, we have evaluated the colour deviation in Delta-E00 with which the various PANTONE and HKS colours can be proofed. On shop.proof.de, the tables are now available for all important PANTONE and HKS colour systems, sorted by colour fans.
A distinction is made between the proofing substrates that we use, since the surface texture and the paper white also have an influence on the representability of the colours. The colour deviations were calculated by the proofing software on the basis of the measured colour space of the proof.de proofing system. Deviations are therefore possible in practice. However, it turns out that almost all spot colours can be simulated quite well in the large colour space of our proofing devices. The smaller the ∆E00 value, the smaller the colour distance from the spot colour reference to the proofed colour. Higher ∆E00 values show which colours can be reproduced more poorly in the digital proof.
As a rough guide: From ∆E00 > 1 a colour difference is visible to the human eye, below it it can only be measured, but not seen.
After almost a year of work the time has finally come. The CIELAB HLC Colour Atlas XL saw the light of day. The new HLC Colour Atlas XL is the basis for all stages of professional colour communication – from design to the finished product. The standard version contains 2040, the new XL version even 13283 mathematically-systematically graded CIELAB colour tones on 74 pages.
The free file package contains the layer PDF version with several gamuts for the analysis and research of colors, as well as the spectral data (380-730 nm) of all color tones for recipe software, an Excel table with the measured values and spectra as well as color value tables for all common CMYK color spaces and sRGB. All files are available for free download under a CC license.
Only the HLC Color Atlas XL printed by Proof GmbH is subject to a fee, as production is very labour-intensive and cost-intensive. We at freieFarbe e.V. and Proof GmbH see the “CIELAB HLC Colour Atlas XL” as a genuine, transparent and high-precision alternative to the hundreds of proprietary colour systems, which often make fast and precise cross-media communication in design and production very difficult.
Adobe has updated its colour picker in the 2019 version. Especially in Adobe InDesign 2019, decimal places are now possible for LAB and CMYK during colour input, which is a long-desired feature especially in the high-end colour area. Up to now it was already possible in Adobe InDesign to enter colour values e.g. in CMYK with decimal places and to write them into the PDF during PDF export, but only integer values were displayed.
In Adobe InDesign 2019, three decimal places can now be entered for LAB and CMYK and can also be read out again. However, these values are not adopted in the automatic labelling of the colour fields, although this can always be adjusted manually.
Also in Adobe Illustrator 2019 CMYK inputs with decimal places are now possible, although only two decimal places are possible here. With LAB, only an integer entry is still possible.
Only Adobe Photoshop still does not allow any decimal places, but only whole numbers, it does not matter whether the file is in 8Bit or 16Bit. This applies equally to LAB, RGB, CMYK and grayscale: In none of the colour systems is a specification with decimal places allowed.
From now on we offer our customers the service to check EAN 8 and EAN 13 codes metrologically. This is important, for example, if you deliver articles for ALDI or HOFER, for which you have to provide proof of readability according to the so-called “3B” standard or better. You can order such an EAN GTIN barcode test report here in our shop.
For this purpose we check your EAN or GTIN code with a modern REA Check ER barcode checking device and prepare a test report according to ISO/IEC 15416 and ISO/IEC 15420:
Other optional parameters are also checked:
For example, in the “Size” field you can see directly whether your code corresponds to the size SC2 preferred by ALDI, for example. We have attached an exemplary evaluation above.
For the measurements we need original packaging with your printed EAN / GTIN codes. All codes will be checked on the day of their arrival and the test reports will be sent to you the same day.
Shortly before Christmas, we initiated a major shop update, and adapted and improved numerous detail functions. But we are especially pleased that the update went without any major disruption for our customers, and that the shop was online and accessible for only a few hours, even though the update had to be carried out at the live shop.
The most important point for us was to update the upload area. The new file upload can now process up to 2GB per file and up to 50 files per article and: The upload now starts automatically, and does not need to be started first. We are thinking about increasing the file limit further here, but we really recommend our customers to simply zip many small files and upload the .zip file before uploading. This helps with the overview, and also helps us in handling.
Another new feature is that now all upload areas of all articles are uploaded in parallel and after successful upload all data is displayed appropriately for the articles. Only after the successful last upload the overview page is updated.
The overview of the loaded data has also improved.
Due to an updated shipping module we have more and more variable shipping methods at our disposal. Thus, starting next year, we will also be able to offer a UPS Express before noon, presumably parallel to the DHL Express before noon.
The most important point for us, however, is that the integration of the external modules has now changed so that we can import updates to the shop without having to touch all external modules at the same time. This will give us a lot of flexibility and allow us to respond even faster to better functions in the future and implement them in the shop.
A lot of changes in the background are security patches and an update to a current PHP version, which makes the shop overall more performant and secure.
Next year we are planning a graphical update of the shop before, which will make the website even clearer and faster.
The 7th Fogra Color Management Symposium was held in Munich from February 12 to 13, 2020, to which I was invited as a speaker for the area of proofing in Session 6. I reported on our tests in proofing for the Fogra58-Beta-Textile-RGB Standard for textile digital printing.
The Fogra Color Management Symposium is one of the events in the field of colour management and brings together scientists and users from all over the world for a two-day exchange of ideas in Munich. A total of 21 speakers and 7 moderators reported on the topics multicolour printing, proofing, print procurement, customer expectations, colour management for 3D printing and colour management for textile digital printing, the topic to which I was also assigned.
I arrived one day earlier, because there was a “Speakers Dinner” the evening before, and I also had to discuss with Jan-Peter Homann and Joe Tschudi the structure and selection of our patterns in terms of textile RGB. On site in Munich we set up the standard light booth LED Color Viewing Light XL HYBRID 2.0 provided by Just-Normlicht and coordinated once again which samples we would show best during the Color Management Symposium.
During the Speakers Dinner I had the opportunity to talk to Jürgen Seitz from GMG, the moderator of my session, and Jeffrey Stauffer from oneflexo GmbH, in order to organize our session on day 2 well. Gerardo Cerros from CMA Imaging Belgium SPRL, the third speaker of our session arrived directly for his presentation. Furthermore we could test our presentations on the Fogra computers and already got to know the lecture room and familiarize ourselves with the stage. On the stage sat the three speakers per session plus the moderator of the session. All presentations, moderations, questions etc. were translated live from English to German and German to English. I held my presentation in German, but I had kept the slides in “Denglish” so that they were understandable for Germans as well as for everyone else.
The complete programme of the symposium can be found on the Fogra website. The topics of the seven sessions were:
1. Managing customer expectations – Managing colours throughout the food chain
2. Creating colour credibility in CMYK and extended gamut printing
3. Real-world multicolour packaging implementations (ECG)
4. Industrial Printing application: High Speed Inkjet beyond commercial and packaging printing
KEYNOTE: Colour workflows in the motion picture world – How HDR & Wide Gamut change the game (Harald Brendl, ARRI)
5. Colour communication for fashion textile applications
6. Colour Proofing for Packacking & textile applications
7. Colour in 3D (3D Softproof & Appearance measurement)
You can download the presentation of my lecture “Proofing in textile printing: Contract proofs for RGB-(FOGRA58) based textile workflows” here
After the session, there were lively discussions at our Fogra58 stand and the fabric/proof comparisons exhibited were discussed. Special attention was paid to a pattern with different shades of grey by Joe Tschudi. The proof was quite neutral grey for the human eye, but the fabric had a clearly visible green cast. In terms of measurement, however, the two patterns were only DeltaE00 0.3 apart for an i1Pro2, and a ball-head meter also showed a similar distance. A nice example to demonstrate the difficulty between textile printing and proof, between measuring devices and human perception.
Many thanks to Andreas Kraushaar and the entire Fogra team for the excellent organisation and support during the entire Colour Management Symposium. An outstanding event that shows current developments in colour management and broadens the view to new markets and segments.
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.
On the last weekend in September the general meeting of the association freieFarbe e.V. took place in Tübingen. From Friday to Sunday, the members worked, discussed, conceived and, as you can see on the picture, ” punted” in and with new products and ideas in the best weather on the Neckar river.
After a meeting with the colour management specialists from GMG on Friday, who support the association with software and proofing media, work continued on the new CIELAB HLC Colour Atlas in the afternoon, to wrap up the day with tarte flambée and wine at Matthias Betz’ house.
On Saturday, the general meeting followed at Lorettoplatz at Proof GmbH, where the past year was discussed and the coming year was touched upon. With the CIELAB HLC Colour Atlas and the DIN SPEC 16699 Open Colour Communication much was reached and accomplished, but numerous ideas need to be evaluated, weighted, financed and worked on.
Present were: From Germany Matthias Betz from Proof GmbH as this year’s host, Jan-Peter Homann from Homann Colormanagement in Berlin, Holger Everding from DTP Studio in Oldenburg and the Swiss Peter Jäger from pre2media in Hombrechtikon, Eric A. Soder from pixsource in Uster and Matteo Baschera from galledia in Zurich.
Due to our involvement with freeColour e.V., at the last meeting in Switzerland the desire for a cross-media tool for designers was expressed with which one can create intersections of colourspaces from the freieFarbe CIELAB HLC Colour Atlas XL.
With Gamutmap, Proof GmbH has now created such a tool, which is available to all designers free of charge. With Gamutmap nearly 100 individual colour spaces can be indicated from 34.250 colours of the entire CIELAB colour space, or intersections from many combined colour spaces can be indicated.
An example: As a designer you are looking for colours for a new corporate design, which are available in sRGB for the internet, in ISOCoatedV2 for printing image brochures and in PSOUncoatedV3 for printing stationery. For video productions, the Rec.709 colour space is also to be taken into account.
In Gamutmap you can now easily select the colour spaces sRGB, ISOCoatedV2, PSOUncoatedV3 and Rec.709 and then click on “show”. After a few seconds you will only see the colours that are available in all selected colour spaces. If you move the mouse over a colour field, you will directly see the absolute colorimetric values of the colour in all selected colour spaces and you can copy them directly to your clipboard.
Since the hex value of the sRGB colour space was also still interesting, this colour space was additionally marked for display. The HLC and Lab values of all colours can be read directly in the colour table. All other colour values can be copied to the clipboard simply by moving the mouse to the desired colour field. For the colour field shown in the example above, it looks like this:
HLC: H005 | L055 | C035
Lab: 55 | 34,867 | 3,05
sRGB: 188 | 106 | 128
sRGB (HEX): #BC6A80
Rec. ITU-R BT.709-5: 188 | 87 | 115
ISO Coated V2 (ECI): 14 | 64 | 27 | 11
PSO Uncoated V3 (Fogra52): 10 | 70 | 34 | 8
We are sure that gamutmap will be a great help to many designers in creating cross-media corporate designs and are very happy that we were able to start and push the project with the members of freieFarbe e.V. For us, gamutmap is “work in progress”, which means: In the coming weeks we will add further functionalities and features to gamutmap. For example, a German version is in progress, and the download of spectral D50 CxF data of the selected colours should be possible in the future directly while hovering over the respective colour field, if the field is in the gamut of the freefarbe CIELAB HLC Colour Atlas XL. Further function extensions are already on our wish list… 🙂
We welcome suggestions, criticism, wishes and any support for the expansion and addition of Gamutmap.
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.
Last Monday, the authors Jan-Peter Homann, Holger Everding, Eric A. Soder and Matthias Betz took another milestone in the direction of free color communication in a final meeting at the German Institute for Standardization – DIN in Berlin: The last open points of DIN SPEC 16699 “Open Colour Communication” were discussed and approved. Now only the English version by Matthias Betz and Eric A. Soder and the final implementation and approval by DIN are missing. It is expected that DIN SPEC will be available for download in August. It is published free of charge as PAS – Publicly Available Specification by DIN in German and English.
In this DIN-SPEC we describe a procedure for precise color communication and color sample creation on the basis of open standards such as CIELAB, HLC, ICC and CXF file formats. We work with mathematical color models, high-precision color samples and exact spectral data as a basis for ink formulation at color manufacturers and service providers. Instead of mutually incompatible commercial standards, we show an open, and open-source approach to high-precision color communication.
Besides the DIN SPEC we are working at full speed on new projects and ideas and on different new versions of our free colour CIELAB HLC Colour Atlas.
Also for us the shop update offers some positive innovations. Following the discontinuation of DHL’s old Intraship service, we can now also create automatic shipping labels for parcels via the new “Send” feature of the DHL Business Customer Portal. Another new feature is that we can now digitally frank address labels for our DIN B4 envelopes using digital stamps and therefore no longer require normal stamps. This is particularly interesting for us when mailing abroad with registered mail, which used to be a tedious process at the online post office, which is now automated. And we can switch between orders more easily.
The next updates are already in planning. Especially the upload area is currently being technically replanned by an external developer, because with the next update the way of embedding extensions in the shop will also change. Probably later in summer the next update will be available as soon as the new modules are available and we have been able to test them thoroughly.
In this DIN SPEC we will define tools and procedures for open and transparent color communication from design to finished product based on CIELAB color values, physical samples according to ISO12647-7 and spectral data in CxF3 format according to ISO 17972.
DIN SPEC describes both the way to create physical samples and CxF spectral data for any CIELAB color values by the user and the basic parameters of an open reference color system, which is available to all users without license costs under a Creative Commons license. The work equipment described in DIN SPEC is particularly suitable for tasks in which colours are defined in design for various production processes and communicated to manufacturing companies by means of physical samples and spectral data. The procedure described in DIN SPEC is intended to enable the production of matt, silk-matt and glossy colour samples on closed unstructured surfaces.
In a way, DIN SPEC is the little brother of the DIN standard. DIN writes: “DIN SPEC is a highly effective marketing instrument which, thanks to the recognized DIN brand, ensures a high level of acceptance among customers and partners. DIN ensures that DIN SPEC does not conflict with existing standards and publishes the standards, even internationally. A DIN SPEC can be the basis for a DIN standard.”
With DIN SPEC 16699 “Open Color Communication” we at freieFarbe e.V. would like to show that with open tools and procedures as well as Creative Commons licenses, in particular the CIELAB standard, ICC-based color management and ISO standards for spectral data, color communication is possible on a professional level.
Further information can also be found on freieFarbe.de
The CIELAB HLC Colour Atlas offers professional users of colour three decisive advantages:
Softproof: A softproof is the color-accurate representation of the print on a monitor. This can be done either at the agency or directly at the printing machine, for example, so that the printer can coordinate the production run with the soft proof.
Contract Proof: The “highest” level of proofing: A contract proof is a very high-quality simulation of the subsequent printing result, and is nowadays actually always produced with special inkjet printers on special paper with special software. The UGRA/Fogra media wedge print makes the proof “colour and legally binding”. In the best case, the media wedge is checked directly during proof production with a measuring device and a test report is glued or printed on which confirms compliance with the tolerances.
Validation Print: A Validation Print has higher tolerances regarding the color deviations from the given standard than a contract proof. It is therefore not “colour and legally binding”, i.e. it does not serve as a contract or “contract” between the designer and the printer, unless both parties have agreed that Validation Print can serve as a colour reference. Validation prints are often used in the coordination process in agencies or as quick templates with good colour matching, as they can also be produced on current laser and LED or other digital printers. Compared to inkjet printing, these printing systems are many times faster and cheaper.
Form Proof: A form proof is often found in print shops; large sheets of paper on which the finished imposed sheets, e.g. of a magazine, are printed. Form proofs are printed with inexpensive inkjet plotters on inexpensive paper and usually look terribly coarse and pixelated, even the colors are terrible. However, the data for the form proof runs through the same workflow with which the printing plates are later produced. This means that what can be seen on the form proof can later also be seen on the printing plate. Thus, the final printing forms can be optimally checked once again to ensure that all fonts, images and embedded graphics are displayed correctly. However, a form proof is by no means binding in terms of colour.
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.