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FLEXO Magazine : November 2009
www.flexography.org NOVEMBER 2009 FLEXO 27 Editor's note: If you would like to get involved and help with any of the efforts mentioned in this article, please contact Bill Pope (firstname.lastname@example.org) at 585-267-5434, or Jay Sperry (email@example.com) at 864-656-3447. to investigate the state-of-the-industry in terms of the pigment availability for pro- cess inks and benchmark the colorimet- ric values from as many ink companies as possible. The inks will be tested fol- lowing the ISO 2846 procedure and data collected and summarized. This will then lead to a report detailing the findings, so that recommendations can be made to update the current ink standards. The project is being managed by Jay Sperry at Clemson University. Another effort we are making is direct involvement with the standards community through the Committees for Graphic Arts Technology Stan- dards (CGATS), which is run by NPES and reports up into ISO. The issue of updating the colorimetric target values for the two ink standards has been raised, and CGATS and ISO are completely open to doing so. Our plan is to conduct the FQC project, then report those findings to CGATS. The updates will then go through the review and voting procedures, and we should end up with current, realistic target values for flexography. SINGLE OR MULTIPLE TARGETS? Even when the flexographic-based ink standards are updated, we will still have the issue of having multiple target values for different printing processes, substrates, and ink systems, which makes for potential confusion. While we will never get away from the reality that different combinations of pigments and substrates produce different colors, there is current thinking in pursuing a one-target approach to specifying the color of process inks and overprints. To paraphrase Mark Mazur of DuPont, there should be just one target for what cyan should look like---no matter what process, pigment, or substrate. This is just the target---it doesn't imply that it can be hit dead-on by every combina- tion of pigment, process, and substrate. If we are to pursue such an ap- proach, and acknowledge that the actual values for ink colors will deviate from the target, then we must rethink how we specify allowable deviations and subsequent tolerances. Going with the Delta E approach is problematic, even if the Delta E(ab) ceases to be used and one of the weighted Delta E calculations (CMC, CIE94, or DE2000) is utilized. In every scenario, knowing the Delta E does not tell you how the color is different---a condition often referred to as "mononumerosous." Instead, and this is being discussed and considered by the standards community, color tol- erancing should be three dimensional, like the CIE L*a*b* color space. Indi- vidual tolerances for lightness, chroma, and hue should be developed for each color with the priority being on hue, then lightness, while maximizing chroma as much as possible. SUMMARY At the end of the day, it's great that standards and specifications exist. Our industry should embrace and utilize them wherever possible, like other industries, so that we can achieve pre- dictable, repeatable outcomes. Flexographic printing/converting is as much a manufacturing industry as any other, and we should implement the proper measurement devices and practices. However, as we continue to move in this direction, there is always the opportunity to improve how we do things, including the standards and specifications we look to embrace. FTA and all of its committees and volun- teers are fully dedicated to this effort and working to further develop the tools, methodologies, and procedures that will continue to help improve the fi- nal, printed output, while also maximiz- ing productivity and efficiencies. And the last piece is education. Un- less we are successful and effective in educating all of the stakeholders in the value chain, we will come up short. In one way or another, each of us has the opportunity and obligation to help educate everyone we come into contact with on a daily basis. Take advantage of the tools, information, educational prod- ucts, and networks that are available to you as an FTA member, and help to continue to position flexography for ongoing, sustainable success.
Sustainable Fall 2009