Offset Printing: How do PMS Colors differ from the CMYK Printing Process?

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Offset Printing is a time-tested printing method which has widespread use in the commercial printing industry. It is very cost-effective for printing medium to large production runs.

An offset press uses printing plates but does not transfer ink directly from the printing plate to the paper. The ink on a printing plate is first transferred to a rubber cylinder, which then transfers the ink to the paper. The ink application being "offset" rather than transferring directly to the paper is the reason this printing method is called Offset Printing.

Offset printing uses two main color systems to produce high-quality images…the CMYK Process and PMS colors. This article explains the difference between these two color systems.

What is the CMYK Printing Process?

The vast majority of projects printed on an Offset press are created with the CMYK printing process. CMYK stands for Cyan, Magenta, Yellow and Key (Black), which are the only four ink colors used in this process. Each of these four ink colors will have its own printing plate, so each color is applied separately to the paper as it moves through the offset press.

The four CMYK ink colors are applied as tiny dots. The dots of each color in the process overlap each other in succession. By printing the cyan, magenta, yellow and black ink dots in various sizes, placements, and concentrations on the paper, different variations of color are created. These color variations create the vivid images we know as full-color printing.

If you look at CMYK offset printing under strong magnification, you will actually see the individual color dots that collectively create a full color image.

The CMYK printing process is referred to by many different names. These include 4 Color Process, 4 Color Printing, 4CP, Full Color Printing, or sometimes just Process Printing. Using only the four ink colors of cyan, magenta, yellow and black, the CMYK process can produce about 16,000 colors.

However, there are still many colors the CMYK process cannot accurately create. Though the CMYK process can approximate these colors, it cannot reproduce them exactly. This is where PMS Colors play an important role.

What are PMS Colors?

PMS refers to the Pantone® Matching System. The Pantone Matching System, sometimes called the Pantone Color Match System, provides a universal standard to ensure precise color matches. As long as the Pantone formulas are strictly adhered to, the ink color will be consistently accurate regardless of where the items are printed.

Currently, there are over 2,000 PMS colors. Commonly referred to as "Spot" colors, PMS colors for the printing trade are displayed in Pantone guides which are used globally by commercial printers, graphic designers, and marketing departments. The pages of the Pantone guide resemble the color swatch strips you'd see in your neighborhood paint store.

Various editions of Pantone books are available to show the specific color formulas, how the colors would appear on coated or uncoated paper stocks, and the CMYK process equivalents that will simulate a given PMS color as closely as possible.

Unlike colors created by the CMYK process, which are "mixed" as dots on the paper as it travels through the printing press, each PMS ink formulation is pre-mixed before it is applied to the paper. Also, PMS colors are most commonly applied as solid colors. So if you examined a printed image made with a solid PMS color under magnification, there would be no ink dots. There would only be solid color.

It is also worth noting that most Digital printing presses cannot accurately reproduce PMS colors. This means true PMS colors are not a suitable option for shorter production runs. However, the CMYK color system is used by both Digital and Offset presses, so CMYK printing is readily available for any size production run.

As mentioned earlier, the vast majority of color print projects are produced entirely with the CMYK process. However, certain projects have a strict requirement to use PMS colors. For example, many corporations use specific colors for logos and other designs related to brand identity. These colors need to be consistent across all forms of print media.

Some printed materials use PMS colors exclusively. This is often the case for business cards, letterhead, and envelopes. Other projects, such as full-color brochures and marketing pieces, might use PMS colors as a supplement to the CMYK process…printing the majority of the piece as CMYK but adding one or more PMS colors to select areas.

When it comes to color printing, Color Vision has all your bases covered. We can produce projects using the CMYK printing process, one or more PMS colors, or a combination of these two color systems. Give us a call at 800-543-6299 and we'll be happy to discuss your printing needs. Or, you can also submit a quote request by clicking here. As always, we look forward to hearing from you!