The Basics of the Specifics
While subsequent articles in this series will go far deeper into each of these criteria, we should discuss them in some small extent here.
ISO 12647-6:2012 Graphic technology – Process control for the production of halftone color separations, proofs and production prints – Part 6: Flexographic printing. This standard was completely redone in 2012 and outlines the hue angles required for non-light-fast inks as: Cyan 233°, Magenta 357° and Yellow 93°.
There are two key points to recognize about this standard. The first is these hue angles are almost an exact match to those in ISO 12647-2, which is the offset standard. The implication is that regardless of printing process, our customers expect visually similar results and flexographic printing is very capable of achieving those results. Secondly, only hue angles are specified. This is a recognition that flexographic printing involves a wide range of substrates and the final chroma will be highly substrate dependent. If the ink hues of two different processes match while the chroma is slightly different, then the two jobs should have a strong visual match, even though one will be slightly brighter.
ISO 15339-2:2015 Graphic technology – Printing from digital data across multiple technologies – Part 2: Characterized reference printing conditions, CRPC 1 – CRPC 7. This standard defines seven characterized reference printing conditions known as CRPCs. The CRPC specifies the relationship between CMYK input data and color measured on the printed sheet. There are seven different CRPCs because not all printing processes are capable of achieving the same color gamut. In our case, we have chosen CRPC 6, which is also known as GRACoL 2013. In other words, we expect this wide web flexographic press to produce work which matches that of an offset press.
ISO 20654:2017 Graphic technology – Measurement and calculation of spot color tone value. This is a new standard that describes how spot color tone values (SCTV) are measured and calculated. It is based on the work of William B. Birkett and Charles Spontelli, and gives an equation for calculating the tone value of spot color tints based on their L*a*b* values. When calculated using SCTV and printed properly, the tone curve should appear linear for all spot colors.
One theme runs throughout these three standards—the importance of setting up the press based on colorimetric values. Early editions of FIRST listed “FIRST densities” for wide web, narrow web and corrugated presses. While densitometry is still a valuable tool for monitoring color on press, it is not sufficient for the color consistency and control required today. You can still find density information in FIRST, as Table 19.4.4 lists “starting densities” for paper, film and newsprint, but everyone involved in the “FIRST in Motion” project will tell you density is not the best approach for setting up a press. You must measure the lightness (L), chroma (c) and hue (h) of the inks.
These three standards clearly define the final desired results, but a lot of work has to be done in order to calibrate the press/printing process to achieve those results. That is what the FIRST methodology is all about. The FIRST methodology is based on ANSI CGATS TR 012-2003 Graphic technology – Color reproduction and process control for packaging printing. The five steps are often shown linearly, starting with optimization and ending with process control. However, it is better to consider this as a continuous circular process that never ends. Every press job can potentially give you more information to improve your process. In the same vein, FIRST itself continues to evolve, from its Premier Edition back in 1997 to the current iteration, FIRST 6.0, released at FTA’s Fall Conference 2017.
Willfully Choosing the Higher Road
There is nothing more fundamental to FIRST than understanding and implementing the FIRST methodology. It is inconceivable anyone would question the value of:
- Determining the optimum components in your process
- Calibrating that process to a known standard (fingerprinting)
- Documenting the information so it is repeatable
- Measuring the output of the process and characterizing for color accuracy
- Striving to continually improve the process
Still, human nature being what it is, there is a tendency to be lazy, myopic, imitative, overly optimistic and subject to confirmation bias. These are all extremely harsh words, but be honest: Haven’t we all been guilty at one time or another of falling victim to our weaker selves? It requires constant vigilance to resist the urge to sit back and fall into complacency.
But wait, you say you’ve tried FIRST and it didn’t work for you? Well, remember that process improvement is a significant part of the FIRST methodology and we saw how material and equipment improvements allowed us to approach a few things differently (like 100 percent GCR and SCTV) than in years past. The process works if you stick with it.
We must prove to ourselves that the higher road is the greater road and anything less is unacceptable. The “FIRST in Motion” team set out with the mission to once again prove to everyone in the flexographic industry the value of the FIRST methodology. Not because there was any question of its value, but to remind us that we must constantly recommit ourselves to doing what is right, not what is convenient. If you think FIRST is 404 pages of theoretical principles with little or no use in the pressroom, you have already lost.
Vincent Van Gogh was both a great artist and scientist. He has been quoted as saying, “Great things are not done by impulse, but by a series of small things brought together. And great things are not accidental, but must certainly be willed.” FIRST is a compilation of small ideas that, when brought together in the pressroom, will enable you to produce your own masterpiece.
About the Authors: Dr. Malcolm G. Keif is a professor in the Graphic Communication department at California Polytechnic State University. His current teaching responsibilities include flexography and cost estimating. He oversees instruction in flexo plating and press operations. In 2004, Malcolm was selected as the Print and Graphics Scholarship Foundation’s Educator of the Year and, in 2015, he was presented with Xplor’s Brian Platte Lifetime Achievement Award. Malcolm currently serves as president of the Graphic Communication Education Association (GCEA). A Cal Poly alum, Malcolm completed his Ph.D. in vocational-technical education from the University of Missouri in 1995.
Dr. Mark R. Mazur received a bachelor’s of science in chemistry from the State University of New York at Albany in 1978, a Ph.D. in physical organic chemistry from Yale University in 1982 and an MBA from Rutgers University in 1987. Mark worked for DuPont for 32 years and has had a variety of assignments, including: product management, proofing, electroless plating, solid modeling and finance. Mark is a frequent speaker at industry events, is the chair of the FIRST Committee and is a member of the FTA Excellence in Flexography Awards Committee. In 2002, he received the FTA President’s Award.
Additionally, he was co-chair of Forum 2008 in Dallas, TX and was the 2009 FTA Hall of Fame inductee.