Expanded colour gamut

Referred to as extended gamut or expanded gamut, seven colour printing (ECG or EG) is the process of adding more colours (usually, but not always, orange, green, and violet) to a conventional four colour process setup. This is popular from two perspectives:  to increase the overall range of colours (a bigger gamut) as well as for production efficiencies – it can be more efficient than supporting many different dedicated special colours.

The benefits of seven colour to a brand owner, or creative, are clear:  an economical, wider, range of colours. The impact of colour for brands can be dramatic, with reports stating that 90% of snap judgments made about products are based on colour alone.

When CPGs (consumer packaged goods) manufacturers are increasing their options for consumers (flavours, sizes, regional preferences…) ECG can offer an attractive way to help improve the visual impact of a package on a shelf.

Vendor claims vary slightly, however.  While four colour offset printing can usually hit about 65% of the Pantone book, 7/c printing covers 90% of the Pantone colours.

For a service provider, the benefits of a 7/c workflow are appealing; more press ‘uptime’ – and capacity – as well as less time and materials used. Separate jobs that would require wash up between different spot colours can also be ‘ganged up’ on a single run, providing further economies. In addition, printers would not need to track multiple colour breakdowns, as well as order, mix, and store as many inks.

ECG is on the rise.  Pantone estimates that 15-25% of all packaging is printed using ECG (based on printers using ECG software), and this is expected to increase more than 50% within the next decade.

7/c redux

ECG has garnered increasing amounts of attention recently, with lots of interest at drupa 2016 (7/c digital presses such as Heidelberg’s Primefire and HP’s Indigo), as well as being a topic of discussion at industry conferences (FTA Forums, Color 2016).

ECG looks familiar though – going back to the early 1990s, there was the creation of the High Fidelity Color Project, HiFi Color, by a U.S.-based industry group led by Mills Davis. The primary goals – larger gamuts, as well as production efficiencies – were the same as today.

At the time, higher costs (licensing and materials), combined with the complexity of creating separations and process control, contributed to ECG’s limited success.

ECG Today

Recently, costs and complexity have come down.  The continuing development of digital workflows and enabling technologies blend together to create renewed interest. Matthew Serwin, Graphic Arts Sales Specialist at Spicers Canada, explains. “Today, shops are running integrated colour management and process control.  They can have end-to-end digital workflows, supporting upfront tools.”  This is a key for success today with EGC.

ECG Tools

There are several options for workflow, but some disclosure: several products listed here are from companies who are generous supporters of Ryerson University, and have donated software and services to the School of Graphic Communication Management, where I am employed. There are many other options from the ones listed here to leverage 7/c.

Leading vendors Esko and Kodak offer popular solutions. Esko’s Equinox system involves building subsets of 4-colour combinations of colours to build tint-build books on a press-by-press basis. According to Esko, the 4-colour combination approach results in more colour data than an ICC 7-colour profile, and ideally results in better conversions to 7-colour. Equinox also offers an Adobe Photoshop plugin that uses these profiles to convert CMYK images into spot colors. It can do this automatically, or a user can adjust which colours get expanded, and by how much.

SPOTLESS is Kodak’s solution for ECG. As with Esko, the software starts with a library of spot colours, which are then broken into digital colour recipes. These are stored for a specified, predetermined, printing condition; a particular set of inks, running on a specific press, and tied to one substrate. The system is supported by a database, which provides the ability to track use, analytics, and adjust the colour breaks as necessary.

One step towards wider adoption of ECG was Pantone’s 2015 release of their Expanded Color Gamut (ECG) Guide, which is built using CMYK, as well as Orange, Green, and Violet inks.

This may seem unusual, a company that specializes in offering a myriad of different spot colours, offering a solution specifically to avoid using those same spot colours.

Pantone, however, sees additional and future value in licensing and communication

As Cary Sherburne reported in whattheythink.com, Pantone GM/SVP Ron Potesky’s explained, “we know that brands and designers want to specify their brand colours using the Pantone language, and this is a great way for them to determine how best their brand colours can be produced”. Pantone sees the ECG as a valuable extension to their product line, and by helping to develop a common language to communicate 7/c, which could help drive ECG markets.

Touch7 is a stand-alone ECG system targeted for designers, production artists, and premedia. Distributed in North America by Color Logic, www.color-logic.com, the Touch7 Photo plugin works with Photoshop to add additional separations to RGB or CMYK images – it can quickly and automatically create the bump (touch) plates required to provide a larger gamut, without additional image masking required. The separations can be further adjusted manually. It’s based on image pixels, not ICC profiles, and supports different plate configurations.

For proofing, Touch7 has partnered with Remote Director, a popular cloud-based softproof solution. Remote Director’s system includes the Touch7 colour palette – this also allows Designers to quickly proof a project, and swap different configurations of ECG, depending on the colours in the source images content.

Standards and Specifications

Bill Pope, Director, Graphic Reproduction Excellence with Caraustar and Chair of the Idealliance Print Properties & Colorimetric Council (PPC) explains that ECG can mean different ink sets, profiles, and process control – it can be difficult to produce, and accurately proof.

To help address this, new ISO standards are being developed and released which help support a more open workflow for ECG.

These include IS0 17972 CxF/X-4 Spot colour characterization data for exchanging colour information as spectral data, ISO 20654 – Spot Colour Tone Value for calculating tone value increase for spot colours, and ISO 20677-1 iccMAX a new format for ICC profiles that better supports tints and overprints. There is also a new file exchange format PDF/X-6n proposed, to provide better support for workflows beyond four colour.

Javier Robles, Director of Technical Service at INX International Ink Co., indicates (via email) that, while there are many different sets of ECG primaries, “most vendors would continue to recommend ISO12647 for CMYK. The aims for OGV could vary, but industry studies are moving towards a consensus on colourimetric aims. I don’t believe this should be a major obstacle to overcome.”

Challenges with ECG

In manufacturing, there can be some challenges associated with running ECG, one is reverse type – smaller knockout copy that would have conventionally run as a single colour spot can pose a registration challenge for printers when it is made of screens of three different colours.

Moiré can be another factor, with so many different screen values.  Pope explains one good way to address this is to “run higher line screen rulings (175), and run the violet separation as FM.”

Pope further explains that other issues for printers involve legacy work; jobs that have used one spot colour in the past, and can’t be matched exactly. Repeatability could be another issue with solids that are built from “3 screens, 3 inks, 3 dots, with overprint traps, registration”.  Large panels of flat colour can also be a challenge to keep within acceptable tolerances.

A further challenge, aside from equipment and process control, is training and support, ECG requires skilled prepress and press people to ensure it meets expectations.

Packaging and ECG

While new tools put the concept of ECG squarely in the hands of creative and brand owners, Pope believes the future of ECG lies on the ‘press’ side.  It will “indirectly drive the 7/c [market], in an effort to drive costs out of the process”.  ECG lends itself well to multiple, shorter, runs and is a great fit for digital, which is one of the reasons for renewed market interest today. With the increasing future growth in packaging, the future success of EGC will be a ‘push’ by printers, and less of a ‘pull’ by brand owners.

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