By the Numbers, Please:
Color Management Improves Digital Workflow

By Noel Jeffrey

Esko-Graphics' Kaleidoscope provides Gamut Viewing, which will predict if a given proofer profile will cover the press color space.

"NUMB3RS" is one of this season's hit TV shows for CBS - a mathematical genius assists his FBI-agent brother in solving crimes by using equations. "Numbers are everything," he's apt to say. Packaging professionals are also appropriating some of that fictional attitude and aptitude. Algorithms for color management do help solve the very real world headaches inherent in digital workflows. They do not stifle creativity.

The challenge is that unless something is done, color just doesn't stay the same from one digital device to another. And, while experts may disagree on the how of doing something, both vendors and customers agree that although they'd like to have color management that's transparent to them. At this point in time, however, what is available is both difficult and complex.

Just what is color management?

Julie Shaffer, Director of Center for Imaging Excellence, PIA/GATF, writing in GATF World's "Technology Forecast 2005" says, "Color management facilitates the translation of specific color information from one digital device to another. When successfully accomplished, it takes into account the capabilities of image-capture devices, display devices, and output devices, ensuring the color displayed on one computer monitor can closely match another, or a proof from an inkjet printer approximates what will ultimately be printed on press."

When most people think color management, they think ICC. The International Color Consortium is a group of companies working to achieve consistent color across devices. ICC is managed through the offices of NPES The Association for Suppliers of Printing, Publishing, and Converting Technologies. According to the ICC, it takes a color management module (CMM) to transform data encoded for one device (such as monitor or scanner RGB) into that for another device (such as printer CMYK) in such a way that when printed it reproduces the same colors as those scanned or viewed on screen.

Mathematical tables called device profiles provide CMMs with the information necessary to convert color data between native device color spaces (RGB, CMYK) and device independent color spaces (CIE L*a*b*) and then to link to another device's color space. ICC's profile specification is currently Version 4 and is in the process of becoming an ISO (international) standard.

Tools such as PANTONE Color Cue and X-Rite Spectrophotometers allow finer callibration, shown here verifying Flint Ink's "Intelli-Print" quality audit sheet.

The specification divides color devices into three broad classifications: input devices, display devices, and output devices. For each device class, a series of base algorithmic models are described which perform the transformation between color spaces. These models provide a range of color quality and performance results, which provide different trade-offs in memory footprint, performance, and image quality. When profiles are applied to a digital device to compensate for variables, the process is called calibrating.

In addition to ICC profiles, many vendors have developed their own profiling systems that may or may not be compatible with ICC's, principally to accomplish highly specialized tasks. In reality, most vendors have not yet developed ICC profiles tailored to packaging. One very notable exception is Creo, in Vancouver, BC (to be acquired by Kodak). Creo offers a number of CTP devices for packaging printers, a full and modular workflow system, proofers, and more. Creo's Profile Wizard product comes as a suite or as modular components. According to the company, the suite contains tools for an end-to-end color managed production system, including tools for creating, editing, and fine tuning ICC profiles and ICC device link profiles for input devices, monitors, and output devices. Profile Wizard handles spot colors and preserves black channel integrity.

More is on the way. During a March 9 webinar sponsored by IPA, the Association of Graphic Solutions Providers, Roland Campa, Gretag MacBeth's product manager of color tools, discussed the new ProfileMaker 5 Packaging Solution, available this quarter. "It brings the open ICC standard to the packaging market, and that's not a trivial thing to do," Campa said. The software consists of three ICC Photoshop plug-ins that enable soft and hard copy proofing, and offers automated, single click multicolor separations. All this is made possible by a patent-pending ICC workflow enabler.

Is it worth the effort?

Software programs like GMG's have background simulation functions (like this one for corrugated) that allow designers to see how the printing press substrate will affect the structure and color of a graphic.

Diane Watt, president of Progressive Color Media, a Flint Ink Company based in Ann Arbor, MI, believes that the business advantages inherent in color management technology account for the increasingly strong interest in the process. "Our clients name costs savings after the initial investment as the most important benefit, followed by time to market," Watt says. "Avoiding multiple proofing rounds and press side checks can represent significant savings."

Progressive Color Media was launched in September last year. The company provides a full range of workflow color management solutions that integrate hardware, software, and services. The idea is to enable printers, graphic designers, publishers, and brand owners to achieve fast and accurate color reproduction, increase efficiencies, and improve brand integrity. Daniel Goodenow, director of sales and services, points out that in the packaging world, brand color management, that is, the consistency of appearance on shelves, is vital to brand owners. Other companies share that insight and offer other color management tools.

Sun Chemical, with global headquarters in Parsippany, NJ, is the world's largest producer of water, solvent, UV and EB curable packaging inks, offering the most products specifically designed for packaging applications whether the printing process is flexography, gravure, offset, screen, or digital. Bob Lorenz, the company's vice president of business development, describes Sun's color management program directed to brand owners as an offshoot to the ink business.

"It's all about speed to market and a reduction of complexity," Lorenz says, noting that approvals for a global product launch can be cut from nine months to three months when color standards are used. "There was a demand for targets to hit," he says. "The Pantone books are references, not targets."

The program, which started about five years ago, is highly customized for each end user. Working with a company's signature colors, Sun develops physical color standards produced on the actual packaging substrates the customer uses. Every few years, Sun refreshes them. In-house designers work from these color targets. These standards include the L*a*b* values for the colors and agreed upon CMC tolerances for the printing processes. Press operators around the world can then actually run to the numbers. Sun also offers software tools that will permit remote inkjet printers to output the actual colors.

"Companies spend millions in advertising dollars to maintain a brand," Lorenz says. "Variations in appearance on the shelf can make a product look bad." He also points out how enormous the consistency challenge is because major consumer companies have certain colors that have to match on cans, labels, bags, bottles, and boxes.

Workflow solutions on the market

Some workflow vendors include color management components. Esko Graphics is only one example. Tyler Harrell, the technical education and consultancy manager at the company, notes the increased interest in color management. Esko's color management tool, Kaleidoscope, which is part of the company's FlexRip, is a device-independent color engine. According to Esko's literature, Kaleidscope "excels in color management of special colors such as Pantone and house/designer colors. It combines CMYK (colorimetric) profiles with patented special color (spectral) profiles."

Harrell says that although Kaleidoscope has been around for 10 years or so, customers weren't using its interface to create profiles. That has changed in the past three years. "Kaleidoscope is back into the forefront," Harrell says. "Color management has become the big buzz word because of the move to digital proofing. Extended gamut colors (like Hexachrome) haven't hurt either."

Harrell says Kaleidoscope's strength is in reading spot colors, and it offers unparalleled accuracy, including in multicolor process printing. "We can calculate overprint characteristics," he notes, explaining that it is especially significant to check the color building process when a spot color is used in one of the separation channels (multicolor process). For example, a special blue for a logo may replace the cyan, and will require alterations in the laydown order and percentages of MYK to accommodate what that blue does to the rest of the image.

Esko also offers a workflow module called InkWizard, which permits user-controlled automatic or manual conversion of both linework and images to a target color set or space, including Pantone's Hexachrome, Opaltone, and FM6 as well as custom color sets. Last November, the company announced that it would be integrating PrintTech's FM6 into its new Scope workflow. FM6 is a technology that uses a special color reproduction of spot colors for packaging applications. It is built on a six-color printing process for offset and, like Hexachrome, can significantly extend the color gamut. "This will be used by prepress departments, and it's also a powerful tool for designers," Harrell says.

Essential tools for digital proofing

GMG's "testPage" shows a typical customer test job that contains elements for evaluating the printing process and building color profiles, including gray balance in both three-color and four-color, dot gain and screen characteristics, spot colors, and trapping.

Digital proofing using calibrated wide-format inkjet printers has been slower to penetrate the whole packaging world because it goes hand-in-hand with computer-to-plate workflow, which has not been as widely adopted in flexo pressrooms as it has in offset lithography plants. The inability of many of the available systems to handle spot colors and/or multicolor process printing is another.

Recently, GMG GmbH & Co. KG, T?bingen, Germany, brought its FlexoProof 04 to market. "It really could be called packaging proof because it is effective for all the processes used - gravure, screen printing, and lithography in addition to flexo," says James Summers, president of GMG Americas. "It takes prepress data in a variety of packaging file formats and generates a color accurate proof on a high resolution output device. There are still a lot of people doing press proofing on the flexo side because they haven't had an accurate proofing process."

FlexoProof also includes the GMG SpotColor application, a solution for managing special colors, a must in the packaging world. Like Kaleidoscope, the product can calculate spot overprint characteristics, and the user can also specify color opacity and the associated print sequences.

Like Bob Lorenz at Sun, Summers stresses the significance of the substrate in predicting color appearance. A perfectly profiled color will vary dramatically in perceived shade when printed on papers, corrugated board, etc. Summers points out that one of the most important FlexoProof features is its ability to match the background substrate color and structure as well as the ability to show the potential effects of misregistration between the printing press units.

GMG has also developed its own profiles for color management, although its system is compatible with ICC profiles. "With ICC profiles, you calibrate the device to itself," he says. GMG profiles change the behavior of the output device, which is very important for exact match-ups of remote devices." Summers, who jokes that profiling is "not for the faint of heart" says that designers can calibrate their devices but that building profiles for proofing is best done at the printer so that the profiles will be appropriate for the printing process.