G7 is very beneficial to learn ABOUT even if you don’t actually use it. G7 is just a modern, commercialized method of what a basic practice was, and still is, to calibrate a printing system. The concept is “calibrate to a neutral gray scale from black through white.” G7 then relies upon ICC output profiles to handle colors. I consider G7 to be for advanced users when the time comes, if it ever does, and that can be just for “perceived” competitive reasons.
Some (most?) RIPs afford the opportunity to image a test file at the calibration step which is before the ICC output profile step. In other words, you may print the control file with no ICC profile affecting it and therefore enabling you to see what the calibration actually is. Too light, too dark, grays not neutral, dark green grays with light magenta grays (color crossover)?
Print your control file without color management. The results will show your calibration. If your print is anything but neutral, your process is not calibrated to any standard. If a client asks what values they should use to create a medium gray background for their sign, what do you tell them?
Mike’s method makes it easier for the typical sign shop to get a very good start on controlling their process. Even if a calibration is not spot on, the subsequent step of ICC profiling can result in proper color balance, and that’s usually the case.
Again, a shop doesn’t have to subscribe to G7 but the basic concept of gray, it would behove them to do so.
