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By Shoshana Burgett

Print companies and converters that use spectrophotometers to monitor and control their printing operations can find gold in those numbers if they do a little data mining, say experts in color measurement techniques.

“When you measure a color with a spectro, the spectral data that you get is like the DNA of that color,” says Brian Ashe, solutions architect for the Pantone Digital Business Unit of X-Rite Inc. in Grand Rapids, Mich. “That data can be a really valuable for anyone in the printing trades because it gives great guidance on things like hitting that color when its run on other substrates and processes, or predicting how the color will look under different lighting conditions.”

And thankfully, print managers and shop personnel don’t need to pore over rows and columns of numbers to unravel a measured color’s DNA or try to understand the exact color that a customer wants.

The whole number-crunching process has been standardized and automated so print shop personnel can access the spectral data of a color specified by the customer through the internet, then compare that data with the measured color is being printed on the shop floor. New software programs make those comparisons easy through the use of clear graphics and enterprise-wide software solutions.

“One nice thing about today’s software for spectral data is that instead of looking at rows and columns of numbers that represent the wavelengths of reflected light that make up a color, you’re getting a graph that gives practical, understandable information — information that clearly shows what changes an operator may need to make on the sheet to produce a consistent color,” Ashe says.

Using spectral data is just the next evolution in the pressroom that’s not unlike the movement a couple of decades ago from densitometers to spectrophotometers for color monitoring and control, using CIELab or CIELCh to define colors. Like that switch, anyone who takes the time to harness the new information can reap some tangible benefits in terms of time and money.

Spot On Color

“It’s time to look beyond CIELab or CIELCh — we want to look at spectral data that’s included in a measurement,” Ashe says. “The big brand owners — the Procter & Gambles, the PepsiCos — all understand the scope of this and take advantage of it. Pepsi knows what Pepsi Globe Blue or Red should be, and they now pass that information along to the printer through the internet — digital color communication — so that the printer can take advantage of it.”

“Color accuracy and consistency are essential criteria in the production of all of our packaging materials,” says Kurt Sands, Senior Industry Manager, Global Procurement-Flexible Packaging at PepsiCo. “Our consumers are acutely aware of the hues of their favorite products and the implied flavor profiles they connote. Programs that establish targets and tolerances for color, based on spectral information and that continuously monitor compliance, are integral in meeting these goals.”

True Colors:how spectral data helps printers large and small to hit their color targets

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People in the packaging industry are concerned about the accuracy of spot colors that sometimes are just as important to conveying a customer’s brand as the logo itself, but those spot colors don’t lend themselves to being read accurately with a densitometer, Ashe explains. Even though brand owners are stressing the value of exact color in packaging, a majority of companies still are measuring by density alone. Some inevitably will be left behind as use of spectral data becomes the norm in the industry, similar to the way that many consumers discarded the cell phone technology of ‘90s in favor of today’s smart phone technology.

“A densitometer is very good at reading process colors — cyan, magenta, yellow, or black: the CMYK of the four-color process — because it basically is looking at the ink film that’s being laid down on paper,” he says. “But while they are very good at checking density, densitometers aren’t very good at looking at color. Actually, they don’t see colors at all.”

Have a Good Roadmap

Like the way a prism can break up sunlight into the colored light components of the visible spectrum, many spectros used on the printing shop floor measure the light reflecting from a color and break it up into 32 points of data that show the spectral energy at 10 nanometer wavelengths. “A spectro gives a mathematical way of describing the color,” Ashe says. “We can say: That’s fire engine red, but what does that mean to someone in China? So we try to have a language of color that is truly an international language, and that means it’s based on mathematics.”

The advantage of determining where a color resides in color space is you can determine how far a measured color is in distance from the desired color — its Delta E*. For instance, knowing how far one color is from another in CIELab terms is a critical piece of information because it essentially gives a roadmap of how to reach the desired color.

“Anything that you can do with a densitometer, you can do with a spectrophotometer — but the reverse is not true,” Ashe adds. “You can measure gain and density with a spectro, but you can also use it to check incoming CMYK inks to make sure you have the right colors before you put them on press.”

This degree of precision is fundamental to developing a standardized way to run a four-color process, instead of running a wide-open process where the printer may be receiving an unsatisfactory range of hues in cyan, magenta, yellow and black.

When the Customer Wants Something Different

The information gleaned from a spectro measurement can also be used to predict how a color ink will appear under different lighting conditions, on a variety of substrates and with different standard observer angles.

“CIELab is handy as a way of describing colors because a lot of people are familiar with it,” Ashe says. “But while it has been calculated from spectral values, CIELab can be a trap because it uses certain assumptions in making those calculations.” Some of those assumptions may be the substrate used, lighting condition, such as whether the color is to be viewed under D50 (5000° Kelvin) or D65 (6500° Kelvin) or whether the standard observer angle of 2° or 10°. In those cases, technicians will have a much easier time properly adjusting the colors to the desired conditions if they have spectral data.

RED

ORANGE

YELLOW

GREEN

BLUE

INDIGO

VIOLET

700nm

600nm

500nm

400nm

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The value of running a process to spectral data really comes through when a press is running spot colors.

Many printers today still try to run jobs based on achieving good matches to colors that customers have picked out in Pantone guidebooks, which are precise chips of specified colors printed on white paper stock through the litho process, at a point in time. But a company running a flexographic press printing on a film substrate may have an extremely difficult, or even impossible, time trying to match those colors because the printing conditions are so different.

“So the brand owner says to the printer: ‘347 Green is my brand, and you have to hit that color,’” Ashe says. “But it may be very difficult for them to achieve, depending on things like process and substrate. To correct that problem we now have PantoneLIVE that has developed dependent standards based on variables such as the process and substrate. So we say 347 Green but on film on a flexographic press, or 347 Green on white litho recycled board paper on an offset press.”

Since the spectral data of PantoneLIVE resides on a server connected to the cloud, a company can access the data at any time and the brand owner can be confident that all of its vendors are working from the same reference files. The PantoneLIVE system has distinct advantages over the widely used process where tangible swatches are used to define colors in the supply chain for checks and approvals.

When paired with the advanced color measurement technology, the PantoneLIVE system ensures that brand owners will receive their desired colors on different substrates, including papers that contain varying amounts of optical brightening agents.

International packaging giant Chesapeake, with 42 facilities that employ more than 5,000 people in Europe, the United States, and Asia, is reducing ink inventories, press time and make-ready sheets throughout its global lithography operations through use of the PantoneLIVE system. Michael Cheetham, CEO of Chesapeake, says, his company experienced a 37 percent reduction in waste and a 75 percent reduction in the color variation on final product at press make-ready in the first year of using the system — with an estimated annual savings of more than a million test sheets.

Chesapeake also estimated that it was able to reduce its inventory of about 3,000 inks to about 540 inks because it had precise spectral data for spot colors that allowed it to formulate colors specified by brand owners from fewer basic inks says Jon Drennan.

“Spectral data can be considered as a DNA of color,” says Kiran Deshpande, print and color management specialist at Chesapeake. “It provides a complete description of color which acts like a unique fingerprint of that color.”

Chesapeake saw a 37% reduction in waste and a 75%

in color variations. In addition, they reduced their ink

inventory from 3,000 inks to 540 inks.

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One technology used by the X-Rite eXact family of spectros can provide enhanced spectral accuracy on color measurement under the more stringent standards being imposed on the printing industry, says Steve Smiley, owner of SmileyColor & Associates LLC, a Red Oak, Texas-based consulting firm that helps companies manage color across a network of digital, analog and packaging supply chain partners globally. “For today’s needs of matching proof to press across many substrates, the eXact brings to the supply chain a simple-to-use device that is fully compliant with ISO 13655:2009 measurement standards.” That makes it a common tool for more accurate color communications that can be used across all supply chain partners, from design through converters.

Jay Sperry, Graphic Commercialization Director of HAVI Global Solutions in Downers Grove, Ill., says that establishing objective color definitions and providing digital communication of brand colors has many advantages outside of accurate color reproduction, including quicker time to market for new packaging, simplified digital proofing, and easy access of true color for creative design and marketing.

As with many technological advances in business, the world’s largest corporations are among the first designating that spectral data be used for its printing work as precise color control reinforces their brands. But today’s technology makes it relatively inexpensive and easy for even small- and mid-sized printing companies to use spectral data to run their day-to-day jobs, Ashe says.

The eXact is the first and only spectrophotometer, having M1

part 1 support, and can be used for both fluorescing inks and

papers. Most other M1 instruments support only M1 part 2 and

can be used only for fluorescing papers.