Expanding the Possibilities of Color

Extended color printing could be the next best thing to the eye of the beholder in the package-printing industry.

PHILOSOPHICALLY SPEAKING, THE exact nature of color may be in dispute forever. As far as brand owners and the package and label printers who work with them are concerned, however, color is a concrete, measurable reality and the most critical component of print quality. If the job of the packaging or label designers is to create shelf appeal and ensure brand recognition, the job of packaging and label printers is to lock in those attributes by reproducing those designs as faithfully, efficiently, and affordably as possible.

Any technology that can make this happen without incurring the expense of additional prepress work or multiple passes through the press will be of special value to profit-minded printers and their price-sensitive customers. Extended color printing, which is said to expand the color gamut beyond CMYK and still deliver a quality product on time and on budget, is said to be one such technology.

Why CMYK won't do

The 4-color printing process known as "CMYK" requires four separations in cyan, magenta, yellow, and black to produce the corresponding printing plates. The fact that the CMYK color space is significantly smaller than the color space visible to the human eye underscores the limitations of 4-color process printing in color-critical applications like fine art and packaging. Violets, greens and oranges, for example, are very difficult to match using 4-color process. Because CMYK has a limited color gamut, it can simulate only about 60 percent of Pantone colors.

Extended color technologies enable the printing of a wider range of colors by adding custom inks to the standard CMYK ink set or by using higher densities of commercially available inks to achieve intense, highly saturated (read: accurate and eye-catching) effects. Nearly 90 percent of Pantone colors reportedly can be simulated with the use of extended gamut printing.

Why extended color?

Originally used to reproduce art, the term "extended gamut color" could apply to color-critical applications from a Van Gogh or Picasso print to any number of high-impact consumer packaging and point-of-sale applications found on grocery shelves around the world. In promising rich solids, realistic skin tones, true pastels and continuous-tone images, extended color printing is an enticing option for brand owners and designers interested in reaping the benefits of high-impact package graphics: greater visual/shelf appeal; accurate, consistent, repeatable color; and market differentiation.

From the package printer's perspective, advantages include less color correction on press; consistent, predictable color that exhibits customer-pleasing sharpness, detail, contrast, and brightness; efficiencies related to use of a single ink set, including time savings and faster makeready; reduction in the need for custom spot colors; and competitive advantages arising from increased press uptime and reduced downtime. When the net result is shorter time to market, expanded color printing can be a win-win proposition for all concerned.

Requirements for extended color

On the prepress side, complex packaging applications that combine process and spot colors require sophisticated trapping, screening, and proofing tools. Among other potential drawbacks, extended color applications can be difficult and expensive to produce because of the need for more plates and special inks, especially in short-run applications.

FM screening is particularly well-suited to high-end printing applications, because the small dots help to accurately render detailed images of fabric, jewelry, automobiles, skin tones and the like, which decorate consumer packaging. Examples include Artwork Systems' Classic and Quantum Hybrid Screening, Kodak's Staccato screening, Esko-Graphics' Monet, Heidelberg's Satin, Agfa's :Sublima XM and Screen's Spekta, as well as new Taffeta screening from Enovation.

Extended color options

Pantone's 6-color process known as Hexachrome and the more recently developed 7-color Opaltone Digital Color process employ six or more process colors such as orange and green to produce—in a single pass—brighter, more vibrant color images than can be derived with standard process inks.

Hexachrome: In 1995, Pantone introduced the 6-color Hexachrome process, which uses reformulated 4-color process CMYK inks plus Hexachrome orange and green, enabling printers to reproduce twice the color gamut of conventional CMYK. By using six colors instead of four, Hexachrome is said to simulate more than 90 percent of spot colors found in the Pantone formula guide. This means fewer press changeovers and washups and the advantage of being able to gang up print jobs for added speed and efficiency because the press can stay configured for Hexachrome instead of changing it every time new spot colors are called for. This eliminates the washup time required between jobs to make ready the press.

Pantone HexWare plug-ins are used in conjunction with Adobe Photoshop and Adobe Illustrator to color-correct files, separate into six channels, and soft-proof images. QuarkXPress is Hexachrome-enabled. Other compatible workflow applications include ArtPro (Artwork Systems), Freehand (Macromedia), InDesign (Adobe), and PackEdge (Esko-Graphics). Compatible color profiling software includes GretagMacbeth ProfileMaker, Kodak ProfileWizard, and X-Rite Monaco Profiler. Hexachrome-licensed proofers include DuPont Digital WaterProof/Chromalin AX4 and WaterProof/Chromalin CV, Fujifilm ColorArt and FinalProof, Kodak Approval XP4 and Matchprint, and Roland HiFi Jet and Jet Pro. A 6-color press, 6-color proofing solution, and specially formulated Hexachrome inks are required to implement the Hexachrome process.

Opaltone: Opaltone reportedly gives digital, flexo, gravure, letterpress, lithography, and screen printers the ability to use CMYK plus Opaltone red, green, and blue (Opaltone R'G'B'). Originally developed for use on high-end drum scanners, the Opaltone R'G'B' color separation algorithm is said to automatically separate up to three additional R'G'B' saturation plates using Photoshop 6.0 or later. The resulting separations complement CMYK without modifying the source image. Opaltone's DCS2.0 format is supported by most RIPs and most popular graphic assembly programs, including ArtPro PackEdge, Freehand, Adobe Illustrator, InDesign, Photoshop, and Pagemaker, as well as QuarkXpress. Earlier this year, X-Rite Inc. and Opaltone Inc. announced a partnership to further develop multicolor profile measurement solutions for the implementation of Opaltone Digital Color. Opaltone-certified proofers include the DuPont Waterproof and Kodak Approval systems.

Spot-on solutions

Use of an expanded digital color palette also reduces the need for the spot inks used to print custom spot colors. This approach—which requires a 6-color press and a computer-to-plate installation—is said to reduce the cost of printing special colors and give designers more flexibility to use them in layouts. Since spot colors are replaced by composite process blends, they can be integrated easily into the workflow and proofed for color and placement.

Developed in cooperation with Esko-Graphics, MAN Roland, Sun Chemical, DuPont, ArtWork Systems and Kodak, FMsix uses a special color reproduction of spot colors for offset and flexographic packaging-printing applications that is said to improve color quality while significantly reducing production costs. The application is built on a 6-color offset printing process and uses an algorithm that delivers a significantly extended color gamut when used in conjunction with FM screening. Esko-Graphics integrates FMsix technology with the InkWizard module in its Scope workflow.

Kodak's Spotless X extended color management module is said to translate spot colors into process color builds within the Prinergy workflow. The spot colors in a print job are automatically identified, and specific spot inks are replaced with process color recipes. In a typical Spotless X example, ICC profiles are used to create Spotless files with images and spots converted into 6-color process blends. This allows full access to the extended color gamut and the use of wide-gamut RGB images. Requirements include a CTP device equipped with Kodak Squarespot thermal imaging and Prinergy workflow with Staccato FM screening. Inkjet proofers such as the Veris contract proofer or the Matchprint family of proofing solutions provide excellent reproduction of Spotless color. The Spotless workflow also supports standard output to third-party inkjet proofing devices. When the donor media matches the extended process colors, spectrum thermal halftone proofers can proof Spotless X printing.

By Jean-Marie Hershey, an author and editor specializing in the graphic communications industry. She can be reached at jmh@writehandcom.com.