By Wayne Peachey, SGS International
Ask an average packaging printer, “What are the characteristics of your print results?” and they will typically describe using subjective terms such as “Sharp,” “Loads of colour,” or “Better than ISO.”
Each statement in itself suggests something good, a selling feature of their particular print process, but if all three printers were to print the same image, do you think they would they all appear the same? If you said, “no,” you’ll be right 99 times out of 100!
Consider all of that time and money spent travelling to press approvals, all of that press time and wasted material due to poor colour management. Standards can help to align printed results to the customers’ expectations, can remove the need for press approvals, and can improve quality. Colour management using standards is the only way global companies can present a consistent brand image, establish customer confidence in their products, and save money across the whole production process.
At a European Flexographic Industries Association round table event last year, I posed the same question. If all of the printers were given the same image, would they all look the same? The question raised some unexpected reactions. Some printers thought I was suggesting that they lower their standards to print like a their competitors, another said that the industry “…needs standards just like the Lithographic printing industry.” In actual fact, those standards have existed for many years.
Not one printer said, “I print to ISO12647-6,” the document that describes flexographic printing. It provides targets and tolerances for the appearance of solid and halftone reproduction.
Now if this had been a meeting between the leaders in the construction or aerospace industries, they would have known exactly which standards were important, and if I had given them the exact same technical drawing they would have each been able to replicate the same product.
So why is the printing industry different (to put it mildly)? Is this due to a lack of awareness of industry standards? Are people within the industry simply not taught the basics
It is probably because printing situations can be very diverse (using substrates and inks that do not match perfectly with ISO standards and those “grey” areas lead to confusion. However, is the right approach to ignore those standards completely?
The range of substrates used in packaging means that not every print condition uses a “plain white” paper. Often poorer recycled substrates are used for cost reasons, or when a metallic appearance is required the image areas are often printed with white, which makes everything look grey
Also, the demands placed on the packaging and the ink due to wear or heat mean that the physical characteristics of ink often trump the colour considerations. This means that different inks and pigments are used in different situations.
The basic marketing strategy behind brand (colour) management
So why is colour consistency important? The best way to understand this is to imagine you are standing in a supermarket faced by two competing products…
-Item A has a nice design, and the image and information tell you that the product is what you need. There are different size options, in both flexible pouches and in boxes. The colour between the flexible pouches is not consistent, and some packages are lighter than others. Are these different varieties, or have some packages been on the shelf longer than others? The boxes show the main colour, but it is different to the pouches.
You wonder if this manufacturer really has an eye on quality, and perhaps the product is inconsistent?
-Item B also has a nice design, and the image and information tell you that the product is what you need. There are different size options, in both flexible pouches and in boxes. All colours are consistent.
This suggests to you that this manufacturer really has their process under control and is proud of their brand.
Finally, how much would you pay for Item A versus Item B? Maybe 20 percent more? That’s why colour and consistency are important. The extra 20 percent has a direct result on the bottom line, leads to more sales, and creates additional value for shareholders.
What are printing standards?
The purpose of printing standards is to help manage colour so that the proof that the customer signs and the printed results across many suppliers all match. This is achieved using a “hub and spoke” approach, with the hub being the “standard” that is held in a large vault in the ISO headquarters in Geneva!
The ISO organization has existed in its current form since 1946. The term “ISO” is not an acronym from any specific language, but the generally accepted abbreviation of the International Organization for Standardization. There is a commonly held belief that the term ISO is short for International Standards Organization but this is not so, and an urban legend that it is based on the Greek word “isos,” which means “equal,” but this has never been substantiated.
A good example of standardization came about in 1825 when the British Weights and Measures act standardized the length of a mile, yard, foot, and inch. Prior to this time, parts for machines could not be created away from each other and then assembled in a factory. Once the Imperial measurement system was established, it enabled the industrial revolution to gather pace; it was the start of globalization. Machine parts created in different places could be brought together and they would fit, and the comparison is even more true today due to the globalization of the printing industry
Standards in detail
The ISO 12647 standard provides standard process control targets and tolerances for various printing methods and processes. Under the general title Graphic technology — Process control for the production of half-tone colour separations, proof and production prints, ISO 12647 consists of the following…
ISO 12647-1:2004: Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 1: Parameters and measurement methods
ISO 12647-2:2004: Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 2: Offset lithographic processes
ISO 12647-3:2005: Graphic technology — Process control for the production of half-tone colour separations, proofs and production prints — Part 3: Coldset offset lithography on newsprint
ISO 12647-4:2005: Graphic technology — Process control for the production of half-tone colour separations, proofs and production prints — Part 4: Publication gravure printing
ISO 12647-5:2001: Graphic technology — Process control for the manufacture of half-tone colour separations, proof and production prints — Part 5: Screen printing
ISO 12647-6:2012: Graphic technology — Process control for the production of half-tone colour separations, proofs and production prints — Part 6: Flexographic printing
ISO 12647-7:2007: Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 7: Proofing processes working directly from digital data
ISO 12647-8:2012: Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 8: Validation print processes working directly from digital data
ISO 2846-1:2006: Graphic technology — Colour and transparency of printing ink sets for four-colour printing — Part 1: Sheet-fed and heat-set web offset lithographic printing
ISO 2846-2:2007: Graphic technology — Colour and transparency of printing ink sets for four-colour printing — Part 2: Coldset offset lithographic printing
ISO 2846-3:2002: Graphic technology — Colour and transparency of printing ink sets for four-colour-printing — Part 3: Publication gravure printing
ISO 2846-4:2000: Graphic technology — Colour and transparency of printing ink sets for four-colour-printing — Part 4: Screen printing
ISO 2846-5:2005: Graphic technology — Colour and transparency of printing ink sets for four-colour printing — Part 5: Flexographic printing
Standards and Specifications
The key standard for the packaging industry is ISO 12647-2:2004. When a printer matches this standard the following occurs…
- The solid colours of CMYK match for colour and strength versus the published numeric values.
- The overprints match, for instance a cyan and magenta overprint area will have the correct colour and strength.
- The “grey balance” is correct, which means the 50 percent Cyan, 40 percent Magenta and 40 percent Yellow areas produce a neutral “grey” without a colour bias.
- The tone curves are correct, which means that (for instance) a 30 percent black looks as expected with the correct “weight.”
As lithographic printing is so prolific, a number of Specifications have been created that provide colour samples and techniques that aid the printer in matching ISO 12647-2 plus any other relevant standards such as the defined ink characteristics.
Standards are a negotiated agreement among over 160 ISO member countries. As new research is conducted, Specifications are developed that bring forward more information. To use an analogy, the Standard defines the requirements of the cake, but the Specification provides the recipe!
In printing there are many Specifications that build upon the ISO 12647-2 Standard. Examples of Specifications in the printing industry are SWOP (Specifications for Web Offset Printing), and Gracol 7 (General Requirements for Applications in Commercial offset Lithography, 7th edition).
Both Specifications are built upon ISO 12647, but provide more specific practical information. For instance, the Gracol committee conducted a series of research tests that better define the “recipe” behind achieving conformance to the ISO 12647-2 standard, and this additional information is published as the Gracol 7 Specification.
Built upon the specifications further are data sets that provide information that for ICC profiles that can be used to adjust colour monitor appearance and colour proof appearance to match a specific condition. Examples are “Gracol 2006,” “Fogra39L,” “Web Coated SWOP 2006.” In Europe, many printers have standardized to Fogra 39L and so a very real connection is made between the Fogra39L proof that is approved for colour and the print that is made conforming to the same specification.
Although Gracol 2006 and Fogra 39L are different—created by different organizations with differing priorities—they both try to match ISO 12647-2, so a job is printed using one and compared versus a job printed using the other, the results will probably look “close enough” within normal commercial environment.
As well as Standards and Specifications, there is one further category that I should mention—this is Method. A number of individuals and organizations have developed step-by-step techniques for matching a proof or press to a standard. G7 is gaining in popularity in North America. There are many others, some of which are provided within colour management software solutions that take the hard work out of the process.
What about Flexography?
Much more has been done to standardize flexography in the United States than anywhere else in the world. This is thanks to the Flexographic Technical Association’s almost evangelical assertion that “flexo is the future.” The benefits of flexography over other print processes have really struck a chord with packaging buyers, and it could be argued that the growth of flexo in North America is largely due to marketing!
Marketing aside, the flexo industry has really worked to improve quality and increase productivity. It has used standards—initially established by the FTA—to align its members to common printed results to improve the match from proof to press, and it has seen this as a way of competing with gravure, as opposed to competing with itself.
The work by the technical members of the FTA resulted in a document called “FIRST.” Target ink colours within FIRST were established by reviewing and averaging its members printed results—a good approach if you want your members’ printed results to match each other, and a path of least resistance be those for cost or technical reasons.
Members signed up the FTA’s document “FIRST,” just as many signed up to the ISO9001 quality programme, as a badge of honour. As a document, it is strong, alive, and evolving, and when I had the opportunity to contribute my part I was struck by my colleagues’ willingness to adopt new and innovative approaches that further advanced the cause.
The problem with adopting an industry-specific standard (such as FIRST’s third edition) was that the flexo standards did not align with any other print process. Consumer Product Companies want their graphics to look the same across all print processes and, therefore, do not appreciate that different ink sets produce different colour “gamuts” that result in different appearances on the supermarket shelf.
The dilemma therefore is this—“Should we each work to print–process-specific standards, or should we all work towards one common print standard (e.g., The Litho standard) regardless of the print process?” I know the technical reasons for the first approach, but as our customer (and the consumer) is our focus, the second approach makes much more sense.
Print appearance is obviously not as clear-cut as the question above, and SGS has worked hard to use the standards as written where logical, and to create the links and exceptions that are needed in the real world. SGS works with most large CPCs and has developed custom colour quality systems that ensure that those specific needs are met. They have also created an SGS-CMS13 (SGS Colour Management System 2013 edition) that can be adopted with minimum fuss or effort on behalf of the CPC. We will talk about this later in the article.
What about Gravure?
Gravure brings about some unique challenges and opportunities. When you take the same image and print it using both Litho and Gravure, they look different. Why is that?
There can be a number of reasons. Like flexo, gravure print often uses substrates and package requirements that present unique challenges. Light-fast, heat-resistant, scuff-resistant inks (and their associated pigments) may not look like typical litho inks. Magenta may be “yellower,” and cyan “bluer.” Also, the ink layer may be thinner, and this brings about an appearance of a more “colourful” result. It’s a little known and often misunderstood fact.
Gravure has traditionally enjoyed some advantages over other print processes when it comes to colour impact. However, Flexo is competing now thanks to advances in HD platemaking technology. The gravure print process can lay down lots of ink, which means much higher densities are available (when compared with Litho). The argument from organizations such as the PLGA and the ERA is that a much more impactful result can be achieved using gravure, and so why should they limit their process to fall in line with other print processes.
Various gravure specifications have been developed, most notably “PACspace” and “PSR,” that aim to create one common goal for gravure. Much work has been done to try to replicate Litho and it is improving, but it has not yet been achieved.
Please see diagram 1a for the comparison between different colour spaces. This shows how the image would look if printed to the various specifications for colour. Each specification refers to, or creates, target solid colours for CMYK, plus midtone appearance.
The first three from Fogra, GRACoL, and SWOP are subtly different. The next two are more noticeably different—the gravure profiles of PACspace and PSR. Japan colour is a Litho profile close to Fogra but subtly different. The ISO Flexo Poly profile attempts to reflect Gracol as closely as possible.
The last two are wildcards. These are profiles provided to SGS by printers, meaning that they have run fingerprints, created profiles, and sent these to SGS for use within colour management. The difficulty is that many costly, time-consuming, and complex adjustments need to be made to approved files before the graphics can be provided to the printer. Also some approved target proofs just cannot be matched under these conditions.
This underlines the need for the adoption of standards. SGS’s viewpoint is that there are standards and specifications in existence that can be adopted right now. In other instances, there are gaps in the techniques and methods. Whilst litho, flexo, and gravure technical organizations work to standardize, there is little evidence of working together, which leads to a mismatch in appearance of products on the supermarket shelf.
Also, some areas such as special (or spot) colours are completely ignored; however, packaging uses these extensively.
SGS has created a specification called SGS-CMS13 (SGS Colour Management System 2013). It is our method for bringing together all printing processes, including digital, so that the differences in printing methods do not impact on the appearance of the final results.
It is an “off the shelf” standard, meaning that consumer product companies can direct their suppliers to this specification and let the process take care of itself without needing to hire a department of colour managers and incur the expense of creating a custom colour management system bespoke to their company. More information can be obtained from Wayne Peachey at firstname.lastname@example.org, or Nigel Cox at email@example.com
The question of standards is not an easy one. I was told this story, at a colour management conference dinner in Chicago. Five colour management ‘gurus’ were debating standards. A waiter approached, listened for a little while, and then interjected, “How can you have more than one standard? If you have a standard, you have just one, don’t you?”
The group was speechless! No one had an answer that could better his statement!