Basics of color and printing
four-color process printing ink
When we think of color, it's helpful to think of spectrums. The visible spectrum contains all of the colors you can see (as represented by the “eye” icon on the chart shown). The RGB spectrum is comprised of the colors that can be displayed on a monitor. The printable spectrum represents the colors we can print using a specific printing process — called “four-color process — or CMYK — cyan/magenta/yellow/black. The printable spectrums are different for desktop color printers, offset presses and commercial digital presses. Adding a spot color (special mix ink) increases the printable spectrum.
The vast majority of printed products — including mass-produced items and large format items — are produced with four-color process. Some colors, such as vibrant oranges and greens — and/or metallic colors — simply cannot be produced in this manner. This is where special mix/spot color/Pantone colors come in.
PMS printing ink
PMS stands for "Pantone Matching System". It is a system with hundreds of colors specified and defined — with books that have been produced with these colors. There's also a book available called the Color Bridge that shows all of the PMS colors and the closest four-color process equivalent. Looking through the book you can see that perhaps 80% of the colors can be matched very closely with four-color process and somewhere between 10% and 20% can't be matched closely at all.
Some organizations select a PMS color as part of their corporate identity, which requires that the actual PMS Ink is used when printing their material. For example, there is no way to closely simulate a metallic pantone color, using four-color process. This is the reason we have five and six color printing presses: we can print four-color process for most of the art and copy and photographs, and then add a special mix/spot color color for an organization's specific brand color. Quite often when printing large areas of solid PMS color, printing companies will apply the same color twice in two different print units; it's called a double bump.
monitors and color
Monitors and desktop printers are impossible to completely calibrate for accurate color representation. Monitors live in an RGB color space — print is CMYK (four-color process) — and desktop printers (including some high-end models) simply don't have the ability to reproduce tightly calibrated color standards. We use Gracol 7, a calibration and certification by a third party licensed to do so, and rely internally on expensive calibration tools to keep our proofing devices and presses in sync.
other articles on color
Our Resource Center has a variety of articles on color for your review. Check these out:
RGB To CMYK... What You Need to Know
For a quick but thorough review of color theory and how it applies to creative, production and printing, look no further than this article.
Heavy Coverage... 10 Job-Saving Tips
10 tips to keep in mind when your print job has heavy ink coverage.
Rich Black Ink
Make your black backgrounds deeper and richer by adding some color to the 100% black ink.
Creating Color Harmonies
Creating beautiful schemes is easy if you rely on any of the tried and true visual harmonies.
GRACol and G7: Standardizing Color Appearance
Standardizing color across your workflow is easier than you think!