Why Does G7 Matter? Come and Learn
If you’ve been in the printing industry for any length of time, you’ve probably heard about G7. But what makes it so important? Does knowing G7 help you in your day-to-day work life?
As a printer, making sure your customer is happy is a top priority. Print buyers — your customers — care about what the final product looks like and if the correct colors have been printed. And that is one of the biggest reasons G7 is important: it controls the visual appearance of a printed piece. Built within G7 are the tools that help assure this great visual appearance.
Lots of standards and calibration methods reference mechanical attributes like dot gain and density — but G7 is the only one that is based on measurement of color and corelates to visual appearance. But where did G7 come from? The guy who invented G7, Don Hutcheson, had photography as a love and a hobby. This love of photography becomes obvious when you learn how G7 works. G7 was designed, with the support of Idealliance, the GRACoL working group at the time, and many contributing industry experts and print manufacturers, to control the same type of gray scale that photographers use, and it produces the same result that both photographers and most print buyers want — good visual appearance. So instead of controlling a press the old way by looking at dots and mechanical print attributes, G7 controls the visual appearance much like a photographer would.
The core of G7 is the control of tonality as well as the gray balance. Tonality is how light and dark the image is, and gray balance is the color of the gray. These factors are calculated dynamically based on the color of the paper and ink set.
In addition to pleasing visual appearance, another benefit of G7 is something called shared neutral appearance. Shared neutral appearance ensures that if a printing system is calibrated with G7 it will exhibit a similar result to other G7 calibrated systems. For this reason, brands and print buyers who print across multiple locations and printing processes prefer G7. It means they can print all over the world and get similar results.
Another great benefit of G7 that I find helpful in my work is having a common target. G7 means I can walk into any pressroom, look at any press sheet, and know how the color should be. It is easy to tell by measuring a gray patch on the color bar if the sheet is close — or completely out to lunch. G7 makes evaluating print easy and simple. And G7 works across different print methods and substrates. Brands use G7 to calibrate across litho, gravure, flexo, wide-format, and electrophotography with similar results. This cuts down the number of versions they need and makes everything much easier and less expensive to manage.
Learning how to use G7 starts with learning the basics. For a print buyer or designer, the basics are often all they need to know to get started and improve their professional life. For printers doing reproduction there are variations on the G7 recipe, all using the same method, but a few differences dependent on the printing process they use. In my daily work I calibrate all types of printing processes. In the past few weeks, I have worked on toner machines, litho packaging presses, flexo presses, and wide-format printers using the same basic method with each process. It works well, and it is easy to understand. Having one method that works across many processes is beneficial for staff because it minimizes the training and tools required.
Initial print trials targeting gray balance and tonality by Idealliance’s GRACoL working group (now the Print Properties Committee, or PPC), led to the inception of G7 as the leading methodology for print alignment and calibration. Idealliance offers extensive training and certification of industry professionals for recognition as industry experts. Idealliance also certifies production facilities, and technology for G7 alignment across the entire print supply chain.
If you are interested in learning more about G7, the Idealliance G7 Expert training class I am teaching this May 24-28 covers the fundamentals of G7, color management, and practical lessons on how to use G7. This month’s class is online. I will be teaching it from my studio with a bunch of measuring devices, printers, and multiple cameras. To make it interactive we supply software you can use during the class, and every time I measure, I will share the measurements, and we will all load and work through it on your machine so you can get firsthand experience.
The typical class contains all sort of people — from designers and salespeople, to press operators and experienced color management professionals. Everyone learns the basics of G7 and how it works. For beginners they learn the lingo, and how to communicate G7 and print. Print buyers and designers learn how to talk about what they want from print. Expert users and printers learn the metrics used to calibrate and evaluate, as well as some new techniques. For more information check out this link!
Editor’s Note: G7® is a registered trademark of Idealliance.