The colors most important to your printing client many be any of the 16.8 million different colors that can be defined within the printing process: How can you possibly determine if your printer has done an acceptably accurate job of matching these target colors when they represent the tiniest needle in a vast color haystack?
It’s a puzzling problem that has troubled buyers for as long as they have been specifying print. We can’t possibly measure every single color, and the standard alternative of making a gut decision based on eyeball judgment is unreliable and prone to error. How can we make an accurate and objective evaluation of color quality without drowning in a sea of data?
“Thin Slicing”, a term coined in 1992 by Nalini Ambady and Robert Rosenthat suggests an effective way out of this quandary. Thin Slicing refers to the ability to make rapid yet accurate judgment based on very limited data. Is there a way that we can “Thin Slice” print buying?
Really, perhaps without quite knowing it, print buyers use thin slicing every time they evaluate a color print job. The buyer may not know the countless factors that can affect the color match of a printed job, but they are still able to make a quick judgment based on a narrow range of patterns that affect overall performance. That’s thin slicing, and it works.
But there are limitations to the intuitive, eyeball-based evaluation process. It is inevitably subjective and liable to outside influences of all sorts. It doesn’t lend itself to documentation, and unconscious bias is hard to avoid. So can media procurement secialists find an objective and quick way to “Thin Slice” their print buy to assure the best possible quality/value ratio?
There is a solution: thinslicing can be automated. Modern press measurement systems make it possible to collect, display and analyze that thin slice of the twenty or so absolutely essential metrics that represent accurately the overall quality of the reproduction. The best of these systems deliver this information in a way that is immediate, sharable, and vivid.
What are the essential elements of color measurement that make print thinslicing both effective and understandable?
- Primary colors: Traditionally thought of as “density”, today we measure the entire color data of Cyan, Magenta Yellow and Black solids. Despite its many years of use, density alone is a weak predictor of overall color accuracy. Colorimetric measurement of primary hues provides a better guide.
- Overprints: The three possible 2 color compinations of the primary colors produce the overprint colors of Red, Green and Blue. These colors are well defined by ISO standards and are strong indicators of overall color accuracy.
- TVI, or Dot Gain: TVI measures the quality of the 90% of the image that is not composed of solids. By measuring that great middle area of color reproduction, TVI or Dot Gain, provides and even stronger indicator of overall color accuracy than prinmaries or overprints.
- Gray Balance: This is affected by all the other components of primaries, overprints and TVI. Gray is also the color most easily discerned by the human eye. Put it all together and gray balance is the single strongest indicator of color accuracy.
- Consistency: A sheet that is too dark on one side and too light on the other side may be great on the average, but is not acceptable as quality printing. Consistency across the sheet and throughout the run is an indispensible element in quality printing.
In choosing a color verification system, look for one that tracks all 5 factors, and delivers them instantly to all parties.