True Colors

Of all the mission-critical elements involved in package production, one of the most critical remains color process control. Prepress professionals, print service providers, designers, and others involved in print production have historically struggled to control and manage color. In the packaging realm, the struggle to achieve consistent color has been elevated to a business imperative as the role of packaging shifts from that of a receptacle for the product inside to a key element in selling the product.

Keep it calibrated

“Color process control needs to be a priority for professionals in any organization who take quality seriously,” says Arjen van der Meulen, director of color, enterprise solutions for Kodak’s -Graphic Communications Group. Color calibration, which encompasses calibrating all processes and devices to a predetermined standard, is a prerequisite for color process control, which aims to maintain those processes and devices in their appropriately calibrated state. Adds van der Meulen, “Color calibration is an essential part of color process control, and is just one of many tasks that needs regular attention to ensure a successful packaging workflow.”

According to Jennifer Garvis, worldwide director of marketing for X-Rite, “If you have a process or device that is properly calibrated, and you are using good process control for consistency, the same process can then be profiled; that profile can be used to make prepress proofing devices match actual printing processes, thus ensuring accurate color communication and reproduction.” Adds Chuck Koehler, color specialist with Heidelberg U.S., “Should [such] monitoring reveal that there is variation greater than allowable tolerances, the information can be used to readjust the initial calibrations.”

Materials created in the prepress department can make or break a press run. Errors in packaging preproduction can be carried through and multiplied across the various print disciplines, substrates, and color sets employed to identify a given brand and its brand extensions. This could have disastrous—and costly—consequences in terms of time, labor, waste, and rework.

“Considering the color management aspect of quality control, the first priority that comes to mind is the deployment of appropriate spectrophotometers and densitometers,” van der Meulen says. “This is true not only in the prepress department, but also in the pressroom, where these instruments can objectively measure color and must be part of regular process control.”

The right toolset

Fortunately, a profusion of such tools—some standalone, some integrated—is available to reduce the risks associated with complex, multicolor package printing by detecting and measuring color changes at various stages of the workflow. In addition to densitometers and spectrophotometers, other instrumentation includes colorimeters, chart readers, plate readers, and profile creation software, as well as camera-based systems designed to measure plates and confirm dot structure and accuracy.

• Spectrophotometers are used to measure color and are useful in creating ICC profiles or printed materials. Because they measure spectral rather than colorimetric data, they provide the most accurate color information.

• Colorimeters, which break down color appearance into numerical CIE values, are used for monitor profiling only.

• Densitometers measure the volume of ink being laid down on a substrate. As useful as they are for prepress process control, densitometers cannot guarantee accuracy in terms of shades of color.

Farther downstream, useful quality-control measures include monitoring press runs with inline camera-based systems and employing multi-channel densitometric systems to read the widest range of colors to and provide the press operator with continuous, real-time feedback, reports X-Rite’s Garvis. It is also a good idea to monitor incoming raw materials (e.g. inks) for consistency and accuracy prior to using them on press, she says. Adds Heidelberg’s Koehler, “It is important to place quality control elements on the press form somewhere that will allow process monitoring. In packaging, many times these are placed on the individual products on flaps or folds so that they can be monitored.”

As part of its comprehensive Prinect production workflow, Heidelberg offers integrated tools that can streamline the process of multicolor calibration and profiling in conjunction with the company’s Image Control spectrophotometric color measuring system. Chief among these are Heidelberg’s Prinect Color Toolbox with Profile Tool, Quality Monitor and Calibration Tool, as well as the recently introduced Near Neutral Optimizer, which can be used to create plate curves that comply with GRACoL7, ISO, or to match different processes and materials on different output devices or presses. According to Koehler, Near Neutral Optimizer uses ICC profiles or user-defined reference values to calibrate directly to the neutral tone characteristics of the reference profile itself, meaning that users no longer have to rely on tone value.

Kodak Colorflow Software is said to align color across devices, enabling integrated color control with Kodak’s Prinergy Workflow System. It unifies all the color elements—such as the creation, editing, and managing of ICC profiles, curves, and spot color recipes—managing the relationship between them and the device print conditions. Using 4- 5-, 6-, and 7-color Kodak Spotless technology allows spot colors both inside and outside the CMYK gamut to be reproduced with process colors rather than special inks. The payoff for printers comes in the form of reduced press downtime and increased efficiency, while designers and print buyers can specify a greater variety of spot colors.

X-Rite offers an array of instruments and software solutions to enhance color management and process control in package printing. Software includes the XML-based CxF Color Exchange Format for accurate communication of color across devices and processes; ProfileMaker Packaging software for the creation of profiles; and InkFormulation and ColorQuality software for ink consistency and control. The company’s line of i1 solutions combine hardware and software for calibration of monitors, scanners, and printers. It includes the i1iSis automatic chart reader with Optical Brightener Compensation and the i1iO automated chart reader that measures substrates up to 10 mm thick, including corrugated cardboard, ceramics, and polybag. Other packaging-specific instrumentation includes X-Rite’s 500 Series, SpectroEye, and 939 spectro/photo/densitometers for print quality verification; vipFLEX2 plate reader for flexographic plates; and vipPAQ multi-channel inline densitometer for flexo and gravure presses.

Sea to shining sea—and beyond

Today’s package printers find themselves increasingly operating in a global environment. The red on a can of soda must look the same in Turkey as it does in Omaha. Likewise, the blue on a label of beer has to look the same no matter where it is printed. Prepress plays a critical factor. Not investing in the tools that help you meet customer demands is a misstep. In today’s economy, making sure a product stands out wherever it ends up is paramount. A lighter red very well might be the difference between the sale and non-sale. pP