The most critical and difficult portion of a print job, of course, is the beginning. A product promotion has been designed and created, files completed, and now it’s time to produce the job. Normally it’s a tight deadline. The challenge? This collateral will need to be printed across multiple types of platforms, with different substrates, and on devices that use different pigments. And possibly in different facilities, located in various countries. Oh, and the client would like for the color to be as consistent as possible across all platforms.
Almost sounds not doable, right? But it is — with the proper planning and taking some time up front to explain and show the customer visually what they can expect on completion.
There are a great deal of print providers, all with different levels of expertise, service, and quality. Producing work in a single facility on multiple devices can be a challenge; producing it in various facilities, with different vendors, is even more so. Choosing a vendor based on how they manage their color workflow in the case of having to utilize multiple output devices to produce a customer’s work is paramount.
Enter G7 methodology. This method was invented to do just that: Create a common appearance among various output devices and facilities. By calibrating devices based on tonality and a shared neutral appearance, pieces printed across various platforms will share a similar appearance. ISO/PAS 15339, which is based on G7 shared neutral appearance, has common datasets that are based specifically on different types of substrates and printing conditions. All with one aim, to create that similar appearance.
Branding and Common Imagery
Many companies utilize brand (or spot) colors as part of their brand identities. Those colors are regarded as critical to the image a company conveys. The association between the color(s) and the company is one that brand owners want to be very tight. Ideally, they want their colors to automatically create a subconscious link between the consumer, the company, and its products.
Think about colors like Kodak yellow or Coke red. These colors are effectively “memory colors” in the minds of the consumer, making them think of the company without seeing the name or knowing the product. Therefore, brand owners hold dear the consistent reproduction of their brand color(s).
Reproducing brand colors, along with other graphics and imagery, can sometimes present challenges, especially when the inks utilized on a particular device are used for both. For conventional print processes (offset, flexo, gravure, etc.), brand colors can often be reproduced via separate spot colors in dedicated print units, while process color (CMYK) graphics are printed separately. However, in packaging applications, especially, it’s not uncommon for spot colors and process colors to interact to achieve a particular color or effect. But the point is that brand colors can be handled separately and more easily.
When it comes to digital printing technologies, in some ways it can seem more complicated, but in other ways it’s simpler. For example, most digital printing processes utilize mainly (or only) CMYK colorants (inks, toners, etc.), or they utilize expanded gamut primaries (Orange, Green, and/or Violet), and may even have the ability to utilize a spot color. This can make reproducing all of the graphics, including brand colors, more challenging. But the good news is that, with proper color management and coordination between devices and processes, it can all be handled by software. Brand colors can be specified colorimetrically (L*a*b* values) so various devices can reproduce them accurately.
But one of the biggest things to take into consideration, especially when attempting to reproduce brand colors, is to understand the color capabilities (or color gamut) of any system and its ability to reproduce the target colors accurately. And, when multiple technologies are being used to produce various printed pieces, it’s important to know which device has the smallest color gamut so decisions can be made about how to reproduce color across all the devices.
The Realities of an Exact Color Match
At this point, the client should be shown contract proofs that represent the color that will be achievable from any particular device on a given substrate. This is the point where questions or concerns from the client may arise. Let’s say, for example, five samples are laid side by side for comparison. They represent the five different devices on five different substrates. The reality: they will all not match exactly.
The uncoated press sheet will look slightly under-saturated due to the nature of the stock it’s printed on. Simply put, the physical nature of an uncoated stock cannot build the ink film thickness of a coated stock, visually showing more color due to a higher saturation level. But gray balance, tonality, and color shades will be comparable.
An about-face to that scenario would be the extra color that can be derived from a wide-format inkjet printer. These devices normally have a much wider color gamut than a traditional offset press. The client should be shown that more color can be achieved for their banners, window statics, and POP collateral, while still maintaining a common appearance with the same imagery from other output devices.
Solutions to Manage Color Across Devices
As was described earlier, different devices with different colorants, and on different substrates, can potentially yield a wide range of color from the same graphics. Therefore, in order to achieve similar color across all those platforms, the graphics may need to be color-adjusted. This may take the form of manual desktop-based editing, which can be arduous, time-intensive, and ultimately not lead to the best results. Or, newer software-based approaches can automatically color-adjust the files very quickly, accurately, and objectively —and thus not be left to subjective adjustments associated with an individual.
Basically, these systems look to understand the “source” (color output from the original device and condition, including substrate) and the “destination” (color output from the target device and condition, including substrate). Then, PDFs are simply dropped into a hot folder where, pixel-by-pixel and element-by-element, the graphics are converted from one condition to another. The L*a*b* color space is used to convert each element from one set of CMYK values to a new set of CMYK values, so you can achieve the color from the original device (the source) on the new device (the target).
Again, it automates the process, achieves excellent results, and does so consistently regardless of who operates the software. In fact, this software can be integrated right into an automated workflow, so no touches are necessary, once it’s all set-up. Various solutions include Alwan’s ColorHub, ColorLogic’s Zepra, GMG’s ColorServer, and Oris’ PressMatcher.
Long-Term Control of Color
When print providers are chosen for long-term production needs, a system that monitors a job’s color parameters while being produced should be utilized to help ensure color consistency. There are cloud-based systems that allow the client to track a job’s consistency in real time while it’s being produced. The print quality parameters are determined beforehand by the facility and the customer.
Identifying and agreeing upon targets and tolerances take the guess work out of the equation and allow the print facility to accommodate jobs that are color-critical and ones that aren’t. This saves time and money for both the facility and the client. Expectations can be met on an ongoing basis, and color consistency can be engineered into every job!
Bill Pope is the Vice President, Technical Services, at PRINTING United Alliance.
Chuck Schonert is the Director of Research and Development at Idealliance.