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Standards, Specifications, & Process control
Chris MurphyColor Remedies™
17.Abr.2013
Terms
● Standards v. Specifications (specs)● Standard v. Standardization● Calibration v. Characterization● Calibration v. Process Control
Specification example
● updig.com – Universal Photographic Digital Imaging Guidelines
Specification example 2
● U.S.– GRACoL (general lithography)
● SWOP (magazines)● SNAP (coldset, newsprint)
● Global– ICC– ISO
What is color?
● A characteristic of objects● A characteristic of light● Something that happens in the observer
Color is an event
● A characteristic of objects, and● A characteristic of light, and● Something that happens in the observer.
Confusion is normal
● You're not crazy.● It's not your fault.● It does take effort to understand and
implement.
Color event: object standards
● Print standards (e.g. ISO 12647)● Ink standards (e.g. ISO 2846)● Paper standards (e.g. ISO/DIS 15397) ● Test chart/target standards
Additional Use Case
● PDF/X-1a – CMYK only● PDF/X-3, PDF/X-4, PDF/X-5 –
everything is device independent.
Color Event: Light standards
● CIE - Commission Internationale de l'Eclairage
● ISO 3664● Designers, ad agencies, marketing
companies, routinely disregard.
Color Event: Observer standards
● CIE 1931 standard observer● CIE 1976 standard observer● CIECAM02
Organizations driving standardization
● Global– CIE, ICC, W3C, (WAN-IFRA), ISO/TC130
● Europe– ECI, FOGRA, UGRA, (WAN-IFRA)
● U.S.– ANSI, GRACoL, SWOP, SNAP, FIRST
Origin of SWOP
● One of the first print specifications.● Designer/Ad Agency driven.
Purpose of specs and standards
● Establish expectations and responsibilities– Content creator– Print supplier
● Consider any large business who makes a lot of something, with an entirely custom process that isn't defined at all.
Process control Standards/Specs
● ISO 12647-2 heatset offset litho● ISO 12647-3 coldset offset litho● ISO 12647-4 gravure
FOGRA characterizations
Web Standards
● W3C– sRGB for all content
● Status of browsers– Only tagged content
● Status of mobile● Status of display technology
Measuring devices
● Densitometers● Colorimeters● Spectrophotometers
Custom vs Standard
● Usually custom is the result of a lack of knowledge
● Can be OK, but involves consequences.– Local instead of regional, or global jobs.– Who does conversion to CMYK?
Use case 1: calibration failure
● Use case of measuring device failure, and measuring device self-calibration failure.
Use case 2: billboard GRACoL
● Inkjet printing, not lithographic.● Customers insist on submitting CMYK,
but the wrong flavor.● Compel large format inkjets to simulate a
press condition.
Use case 3: PDF & Proofing
● Customer spends more than $1 million per year on proofs and corrections to files they shouldn't need.
● Moved to a PDF workflow, with direct proofing of the PDF file itself.
● Combination of standards: PDF, ICC.● TR 006 is the basis to verify proofing
system.
Use case 4: Global print markets
● Simply easier to print correctly, consistently, anywhere, with standards.
Standards, Specifications, & Process control
Chris MurphyColor Remedies™
17.Abr.2013
Terms
● Standards v. Specifications (specs)● Standard v. Standardization● Calibration v. Characterization● Calibration v. Process Control
There is a difference between standards and specifications. A specification doesn't speak to any process of building consensus among relevant parties. But a specification can be every bit as detailed: the specifics.
Standardization indicates organized effort to produce, and widely implement a standard. Since it's voluntary, the idea is members benefit from adoption of the standard, and therefore it's in their interest to establish broad support for it in their industry.
Calibration means changing the behavior of a device: display, scanner, camera, printer, printing press, etc. to a reference behavior. The purpose is optimization, and consistency.
Characterization, also known as (color) profiling, most often ICC profiles. The purpose is to record device behavior not directly change it. Calibration is a pre-requisite.
Process control is essentially the same thing as calibration, but is a term that tends to be used for printing. For example calibration doesn't sufficiently convey the effort to make a printing press behave consistently, which means first having very consistent ink supply, consistent paper supply, a press that's mechanically in proper function, I'm leaving out a lot of information here, but for designers and photographers, understand the printing presses are not easy to operate consistently. It takes a lot of knowledge and effort.
http://ec.europa.eu/research/industrial_technologies/pdf/handbook-standardisation_en.pdf
Specification example
● updig.com – Universal Photographic Digital Imaging Guidelines
Should you follow it? Well, the web site is a bit stale. But this is a good example of a basic but reasonably detailed specification. It discusses things as practical as a file naming convention, to file formats to use, not just color management. This is intended mostly for photographers whose content will end up in publications such as magazines or newsprint. But it's broad enough to be useful in other cases.
Another one is Digital Photography Standards and Practices, by ASMP:http://www.digitalphotographystandards.com/
Specification example 2
● U.S.– GRACoL (general lithography)
● SWOP (magazines)● SNAP (coldset, newsprint)
● Global– ICC– ISO
This example is very formal, and is effectively the set of U.S. Standards for these types of printing, even though they're called “general requirements” and “specifications”. It's just that American printing companies historically are averse to conforming to standards.
GRACoL = General Requirements for Applications in Commercial offset Lithography. This is the broad U.S. Specification, equivalent to ISO 12647-2.http://www.idealliance.org/specifications/gracol
SWOP = Specifications Web Offset Publicationshttp://www.idealliance.org/specifications/swop
SNAP = Specifications Newsprint Advertising Productionhttp://www.snapquality.com/
You notice the curious case that IdeaAlliance maintains these specifications (standards), while ANSI, the American National Standards Institute only publishes standard characterization data for print conditions conforming to those specifications.
ICC = International Color Consortium, they publish the ICC profile format specification, also called ISO 15076.
What is color?
● A characteristic of objects● A characteristic of light● Something that happens in the observer
Classic answer is that color comes from objects. The seemingly scientific answer is that color comes from light. And the most interesting is color occurring in the observer.
Color is an event
● A characteristic of objects, and● A characteristic of light, and● Something that happens in the observer.
Colo seems intuitive to us, but really many things are going on all at the same time. But in order to have standardization, and use process control to obtain consistency, we actually need to separate these things so that it's possible to understand and quantify them independently from each other. This is not intuitive at all.
Confusion is normal
● You're not crazy.● It's not your fault.● It does take effort to understand and
implement.
Color management is a difficult subject. The biggest business benefit comes at the most advanced levels. Just like scoring in professional soccer. That's success! But of course you need to have the basics down before you can do that, and often the basics aren't that interesting.
Advanced concepts, actual implementations, are interesting and beneficial. To get there takes hard work, and to not get discouraged. It's normal to be confused. Just keep working at it, and ask questions.
Color event: object standards
● Print standards (e.g. ISO 12647)● Ink standards (e.g. ISO 2846)● Paper standards (e.g. ISO/DIS 15397) ● Test chart/target standards
http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=52214
UGRA/FOGRA produce the Media Wedge control slug for printing on every press sheet. Any sheet can be measured and compared to the reference condition, to confirm/deny with very few measurements if the sheet conforms to established print tolerances.
Additional Use Case
● PDF/X-1a – CMYK only● PDF/X-3, PDF/X-4, PDF/X-5 –
everything is device independent.
For many years Time Magazine only accepts PDF/X-1a for advertising, and more recently only does soft proofing.
Color Event: Light standards
● CIE - Commission Internationale de l'Eclairage
● ISO 3664● Designers, ad agencies, marketing
companies, routinely disregard.
CIE defineds such things as the standard illuminants which form the basis of measuring color on objects, and of course we need light to get color so we have to separately have standards defining light sources and illuminants.
ISO 3664 pertains to illumination of prints. The amount of light affects how the print will appear. So we need to define quantities of light for evaluating prints. P1 “critical comparison”specifies 2000 lux. P2 “practical comparison” is what the ICC is predicated on, specifies 500 lux.
Color Event: Observer standards
● CIE 1931 standard observer● CIE 1976 standard observer● CIECAM02
The first two cases do not take color samples in context, that is, the testing was done with only one color at a time to determine human response. They aren't color appearance models.
The second case tries to incorporate the affect of variation in ambient lighting, and surrounding colors. This part is quite interesting, and an active area of research.
http://www.echalk.co.uk/amusements/OpticalIllusions/illusions.html
Organizations driving standardization
● Global– CIE, ICC, W3C, (WAN-IFRA), ISO/TC130
● Europe– ECI, FOGRA, UGRA, (WAN-IFRA)
● U.S.– ANSI, GRACoL, SWOP, SNAP, FIRST
ECI is a good general repository of information and PDF test files, including the Altona Test Suite, compromising both synthetic and photographic (real) test images.www.eci.org
FOGRA publishes a number of legacy and current standard characterization datasets. If your press conforms to the applicable standard and print condition, then you don't need to go the trouble of profiling your press. The characterization is at FOGRA, you can build your own profile, or possibly use one built by ECI.http://www.fogra.org/en/fogra-standardization/fogra-characterizationdata/a-icc-en.html
UGRA sells tools that aid in press process control, and also seminars, conferences, training, and certification.http://www.ugra.ch/
WAN-IFRA is the World Association of Newspapers and News Publishers. Naturally the U.S.'s outfit is separate, using SNAP as their guide.http://www.wan-ifra.org/
Origin of SWOP
● One of the first print specifications.● Designer/Ad Agency driven.
I'm including this slide specifically to point out that while I made fun of designers and ad agencies earlier about lighting conditions, they clearly understand the need for agreement and the need for print standards.
Purpose of specs and standards
● Establish expectations and responsibilities– Content creator– Print supplier
● Consider any large business who makes a lot of something, with an entirely custom process that isn't defined at all.
Whether you call them standards, specifications, guidelines, the main point is to establish expectations, responsibilities, and to avoid conflict and mistakes.
If they aren't doing this, why have them, or follow them?
Consider Coca Cola. Do they custom make each can of coke? No. Why not? Why isn't custom good for their business model? It's inefficient. To grow, Coke had to invent a modern manufacturing process, to improve product consistency, reduce mistakes and waste, and make as much product as possible in as little time as possible.
The problem with printing in the U.S., historically at least, has been a resistance to making printing a modern manufacturing process. This has changed in the past few years and continues to change.
Process control Standards/Specs
● ISO 12647-2 heatset offset litho● ISO 12647-3 coldset offset litho● ISO 12647-4 gravure
These really apply to printing companies, and even companies who make printing presses. Not graphic designers or photographers.
GRACoL actually is ISO 12647-2 compliant, but as it turns out there are still some subtle differences in actual press behavior, and some of the implementation details. So there isn't exact parity. And as a result, there are different standard characterization sets. ANSI publishes CGATS TR 006 for GRACoL, where FOGRA publishes a litany of heatset lithographic print conditions.
FOGRA characterizations
Web Standards
● W3C– sRGB for all content
● Status of browsers– Only tagged content
● Status of mobile● Status of display technology
Controlling color on the web is increasingly important because of the divergence of display technology, including mobile, from sRGB. So either a revised sRGB is needed, or we need to color manage displays individually. Both are difficult.
There's a very large cost to color mistakes on the internet, especially in textiles purchases not meeting the expectations of the user. However, due to such high variation in user environment, the display is not the only source of this problem.
Measuring devices
● Densitometers● Colorimeters● Spectrophotometers
Main idea is densitometers don't measure color, but can be used for calibration/process control. A densitometer measurement for a known inkset equals a color; but two different inksets will produce different measurements even for the same color.
Custom vs Standard
● Usually custom is the result of a lack of knowledge
● Can be OK, but involves consequences.– Local instead of regional, or global jobs.– Who does conversion to CMYK?
Most of the time people are using custom because of a lack of knowledge of standards, or how to implement them. Custom can be OK but requires more effort to custom profile the press, and then someone must properly convert to CMYK. Who does this? The customer or the printing company?
At the very least, a printing company with a custom printing condition is obligated to supply customers a custom ICC profile for the unique printing condition.
Use case 1: calibration failure
● Use case of measuring device failure, and measuring device self-calibration failure.
The issue here is that measuring devices themselves need to be calibrated. And even their ability to calibrate themselves needs to be questioned, and tested against another measuring device.
It is possible for measuring device self-calibration to pass, and yet it shouldn't. This is a false positive.
Use case 2: billboard GRACoL
● Inkjet printing, not lithographic.● Customers insist on submitting CMYK,
but the wrong flavor.● Compel large format inkjets to simulate a
press condition.
In this case, the customers should be submitting RGB because they don't really know the output intent that will be used for billboard printing. They don't know what CMYK profile to use, so no conversion to CMYK should even occur.
But it does occur because, a.) they're subborn and b.) they already prepared the artwork for magazines or brochures and now want a billboard version.
First all billboard printers are calibrated so their 100% and 50% CMYK patches measure the same with the same inkset. This is arguably too simple, but works better than nothing, but there's room for improvement in the area of inkjet calibration/linearization.
Next, all billboard printers are characterized, each one has its own ICC profile because the calibration doesn't do quite a good enough job of making all printers behave like each other. They're each optimized as best as the software/hardware allows. If it were better, we'd only need one profile for all of the printers. This is more than 75 very large billboard printers. It's a huge amount of work.
Incoming CMYK files are assumed to be GRACoL 2006 (TR006), approximately FOGRA39; and a CMYK-CMYK conversion to “billboard CMYK” is done. In effect the billboard printers are GRACoL proofers!
Use case 3: PDF & Proofing
● Customer spends more than $1 million per year on proofs and corrections to files they shouldn't need.
● Moved to a PDF workflow, with direct proofing of the PDF file itself.
● Combination of standards: PDF, ICC.● TR 006 is the basis to verify proofing
system.
Customer is now saving millions of dollars a year because of the transition to a PDF workflow, and doing their own in-house proofs for the bulk of their most straightforward book covers: CMYK, and CMYK with one or two spot colors.
PDF and the ICC file formats are standards. In this case, more than one standard was used to implement the workflow.
GRACoL/TR006 (similar to FOGRA39) is the basis for confirming the status of the proofing systems. However, the printing company inkset is non-standard and they consider it too expensive and not worth it to conform. So they've built their own press profiles, which include the effect of various laminates and coatings.
Use case 4: Global print markets
● Simply easier to print correctly, consistently, anywhere, with standards.
This is a sad use case where the company didn't understand that the whole world doesn't print with the same standard. And that to get around this, they would need to produce regional specific CMYK files, for the content to print consistently all over the world.
When they learned what they needed to do, they decided it was easier to just keep blaming their printing companies for the problem.
