The packaging supply chain is under pressure—particularly from brand owners—to reduce the cost of package production while increasing quality, compliance and sustainability. Consolidation among brand owners is creating downward price pressure because of demands for reduced cost. Packaging is a major cost and, therefore, a primary target.
One of the ways the package printing industry has become more efficient has been to adopt expanded gamut (EG) process printing. EG has long been viewed as a technology that could deliver higher quality at a lower cost, but many of the tools available to adjust packaging graphics from custom spot colors to EG have been proprietary, expensive and out of reach of all but the largest converters and trade shops.
Also, the lack of empirical data about the accuracy of spot color matching, the complexity of systems to date, and the reliance on standardization of process control have slowed the acceptance of EG in packaging, except in segments like generic and store brands where the cost savings outweigh the risk of a color mismatch. This, however, is quickly changing.
Ryerson University, under the direction of Dr. Abhay Sharma, a professor in the School of Graphic Communications Management, recently conducted its evaluation of spot color reproduction in multicolor printing, on digital printers—separating the accuracy of a prepress system from the variability of a traditional printing system.
In general, findings showed that EG printing can replace cumbersome conventional spot color workflows, creating considerable savings and advantages, especially for label and packaging printers. One conclusion of the study is that EG solutions for spot color printing produce totally acceptable results.
Technology & Tolerance
For many types of package printing, especially wide web flexible packaging, EG is being widely investigated and adopted. In fact, a good percentage of new capital investment is spent on EG-based production lines. The efficiencies created by EG outperform traditional converting methods—CMYK + spot—and the economics—fewer plates, less ink, combo printing—are almost always beneficial. In the US today, there are already many brand owners that rely on EG methods extensively.
It’s also worth noting that the highest quality digital presses available today have adopted variants of EG for their own spot color matching, so using EG for conventional flexo printing allows for repeatable flexibility in hybrid digital and conventional production environments.
Ryerson University’s conclusions validated that additional colorants to CMYK, such as orange, green and violet, truly expand the color gamut, but also showed that different color management solutions produce very different CMYKOGV builds to try and achieve the same colors.
In labels and packaging, there is a general requirement to reproduce spot colors to within a tolerance, typically < 2 Delta E. The study showed that a number of vendors could reproduce at least 80 percent to 90 percent of the PANTONE+ spot color library on both Epson proofers and HP digital production systems, to < 2 CIE Delta E 2000.
Proprietary Methods
For EG to move beyond current applications, it must become a repeatable manufacturing process. Today, a new generation of software tools greatly reduces the time and material expense of fingerprinting and operator skill required to make the process work reliably.
Many existing EG processes are a mix of products and proprietary methods that have evolved over the past 20 years. EG was first successfully achieved in the 1990s with the introduction of Agfa’s Crystal Raster Stochastic Screening. Stochastic screening avoided moiré patterning that had previously limited process printing to three or four channels. EG solutions quickly became available from other vendors.
While these EG processes work, they require high levels of color expertise and extensive fingerprinting and profile creation, so they can be inherently expensive, cumbersome and difficult to reproduce. Thus, the ability to convert a job to EG and produce high-quality plates has typically been possible only for larger, more sophisticated converters and trade shops, and the cost savings found in the pressroom are diminished by the additional prepress required.
Another issue reported by the Ryerson study was that Adobe applications have some challenges when working with files containing more than four process colors, specifically the Adobe PDF Print Engine (APPE), Acrobat Pro, Illustrator and Photoshop. Earlier versions of APPE limit the number of allowable spot channels in a file—the number of color channels APPE can output at once. While they report that this limit may have been removed in the latest version of the APPE, some vendors may not have updated their products.
Ryerson saw instances where color management products, based on the APPE, would not process the test file that contained 1,800 spot color channels. The other Adobe applications mentioned here, used for both graphic design and PDF inspection, also had issues displaying files with large numbers of spot colors, so other applications were needed to allow examination of all 1,800 spot color channels.
EG can make a strong technical impact by significantly improving print quality along with making color compliance easy and reliable—in fact, with an integrated, close-to-perfect proof-to-press match. If done automatically, operators with a reduced skill set can still provide consistent results. Of course, the initial investment cost of setting up an EG capability with dynamic profiling can be recovered quickly because of the inherent economic benefits of EG.
“The efficiencies created by expanded gamut outperform traditional converting methods—CMYK + spot—and the economics—fewer plates, less ink, combo printing—are almost always beneficial.”
Open Process
Instead of investing in a single, proprietary system, the EG separation process can be performed with a few simple integrated applications, thus helping package printers and trade shops create higher quality packaging, more easily, at a reduced price, using software tools they may already own. So, how can an open approach to EG conversion help printers and converters?
An open process solution has obvious economic benefits:
- End of traditional press fingerprinting: With the right profiling tool, fingerprinting is virtually eliminated
- Drastically reduced makeready and lower printing costs: Along with fewer washups; pretty much available from any EG solution
- More than twice the time savings from many prepress processes: This comes from an easier process for color management
- Profit margin improvements across the entire business: As EG is able to standardize methods throughout production
- Lower ink inventory costs and much less ink waste: Which comes with any effective EG process
- Material savings: Fewer makereadies means less substrate and time is wasted between production runs. EG also reduces the need for a large anilox roller inventory as the process is standardized
- Ability to gang jobs: Reducing print costs and increasing throughput in the pressroom
In addition to economic benefits, this solution also delivers:
- Significant print quality improvements with the ability to hit more Pantone colors and the possibility of greater vibrancy in images
- Color compliance made easy and reliable
- Close-to-perfect proof-to-press match, if the proofing solution can be relied upon and accurately represent overprints and EG process builds for both digital and conventional processes
- Reduced skill set with more consistency across multiple operators, in a process that is simpler to operate