These circles may seem like just color splotches, but they hold important printing info. As an old General Mills blog (quoted by Slate) said, they help understand how a printer is working to ensure consistency. They give “technical info about printing conditions” so printers can adjust quickly.
If a color isn’t printing right, printers can spot and fix it, either adding or reducing a color. Modern printers can sometimes “read” these colors for adjustments. But human operators usually make the final tweaks, as Dillon Mooney (a Printing Industries of America technical consultant) said.
Not all packaging has these circles. It’s mostly a matter of preference, as they don’t affect food health or safety. Understanding their role, you might respect printers who think they can get accurate colors without them.
So, now you know more than you probably wanted about those mysterious colorful circles on food packaging. They’re about graphic design, not snack quality. But they offer an interesting peek into packaging design, more fun to think about than nutrition facts.