Printing Terminology: What is CMYK?

estimated reading time: 3 minutes

What does CMYK stand for?

CMYK stands for Cyan, Magenta, Yellow, and Key (Black). These are the four ink colors used by commercial printing presses to create full-color printing. By using just these four inks, approximately 16,000 color variations can be produced.

The CMYK Printing Process

As the paper, cardstock, or other substrate moves through a printing press, the four CMYK ink colors - Cyan, Magenta, Yellow, and Black - are applied one after the other in succession. Each layer of color is applied as tiny dots.

This system of printing is commonly known as the CMYK Process, 4-Color Process, or simply Process Printing.

When viewed individually, the four ink layers yield images that are barely recognizable (see illustration A).

But collectively, the four inks produce full-color designs and images that are vivid and detailed (see illustration B).

Welcome to the Grand Illusion of CMYK Printing

As mentioned, the CMYK ink colors are applied as tiny dots. These dots are only applied in four colors, but their relative placement on the printed sheet creates an illusion that tricks our eyes.

When we look at a finished piece that has been created with the CMYK printing process, instead of colored dots we see colors that are solid and continuous. And instead of just four colors, we see hundreds of color variations.

Here's an experiment you can do that will help illustrate this point: Find something printed in full-color, like a brochure or magazine. First, look at the colorful images from a normal viewing distance. They will appear clear and sharp as if they are solid colors.

Then, look at the images under extremely strong magnification (such as with a jeweler's loupe or printer's loupe). This time you will only see tiny dots of cyan, magenta, yellow, and black (similar to Illustration C). Quite fascinating, wouldn't you say?

Cyan and Magenta

Of course, Yellow and Black are colors you learned about in kindergarten. But the colors of Cyan and Magenta aren't as commonly known.

What Color is Cyan?

It is difficult to accurately describe a color using words, but Cyan is a bright hue that falls between blue and green. Most people see Cyan as more blue than green. Refer to the color wheel below for a visual representation of Cyan.

What Color is Magenta?

Magenta is a pleasing hue that falls between red and blue. That said, most people consider Magenta to be closer to red than to blue. Refer to the color wheel below for a visual representation of Magenta.

And finally, why is a "K" used to designate the color Black in CMYK?

There are two schools of thought regarding the use of the letter "K" for Black.

One explanation is that using the letter "B" would have caused confusion with the color Blue, so the last letter in the color Black was used instead. A second explanation, which is the one most commercial printers ascribe to, is that the letter "K" stands for Key. In this case, "Key" meaning crucially important to a print production run, like a Key color or a Key printing plate.

When CMYK Printing was invented in the early 20th century, Black ink had already been in use for centuries. Since the color Black provides strong contrast, which adds definition and detail to a printed image, it is crucially important or "Key." Hence, when calibrating a production run, Black would be the Key Color used to line up or register the other three CMYK colors of cyan, magenta, and yellow.

If you have a full-color printing project you would like to discuss, give Color Vision a call at 800-543-6299. Or, if you know your specs and would like a quote, click here to submit our Quote Request form.

As a full-service provider, Color Vision has both offset and digital printing capabilities. So, whether you need a short, medium, or long production run, we have the expertise to make your printing project a success. As always, we look forward to assisting you!