By Larry Witzel
October 5, 2011
In theory, using color in print is pretty easy: just pick your color and apply it appropriately. In practice, however, there are some subtleties that can cause problems if you’re not careful.
Electronic vs. Print
The biggest issue is the difference between colors on an electronic display, such as a television or computer monitor, and those in print.
Electronic displays create full color by combining the light from three primary colors: Red, Green, and Blue, often abbreviated “RGB.” Each individual dot on a display, called a “pixel,” is actually composed of three small pinpoints of light, one for each RGB color. For most of today’s displays, each color in each pixel can be set to a value between 0 and 255, resulting in millions of possible colors. When you add all three together at full strength (each at a value of 255), you get white. When they are all off (each at a value of 0), you get black. Other combinations will display nearly every possible color.
However, printing uses pigments, not light, to create full color. The most common method is called “four-color process,” using these four colors: Cyan, Magenta, Yellow, and Black, often abbreviated “CMYK.” Dots of each color, of varying size, are put on the paper and combine to display nearly every possible color. If you were to combine full-sized dots of CMY together, it would make a very dark, almost-black color. Since neutral grays and black are an equal combination of these three colors, black is used to reduce the amount of actual ink required to create darker colors. To create white (or whatever color the paper is), you would put no dots of any color.
The problem is that colors created from light don’t look exactly the same as colors created from pigments. So when you’re looking at a printing proof on a screen, it can’t show exactly the same colors that will be printed.
But it gets even more complicated. The way RGB colors are created is slightly different on every electronic display. And the way CMYK colors are created is slightly different on every printer. Furthermore, different printing methods, such as laser printers, inkjet printers, or offset printers, combine CMYK colors in slightly different ways.
So while you and I might be looking at the exact same digital file, because we’re looking at it on different monitors it will look different. And your laser print of a file will have slightly different hues from the final, offset-printed piece.
Most people won’t actually notice these subtle differences. But occasionally, when someone’s monitor is especially uncalibrated, they might notice a slight shift in color from what they were expecting from an on-screen preview.
To reduce surprises, follow these tips:
- Calibrate your monitor. There are several websites that offer color calibration tools, such as www.displaycalibration.com. Also, both Windows 7 and Mac OS X have monitor calibration tools built in. Use them to adjust your monitor settings so that it most accurately represents the color spectrum.
- Use Pantone colors. If you need to select a precise color, use the Pantone Color Matching System. Pantone offers printed color chips with reference numbers, so when you select a color you can communicate exactly that color using the Pantone or PMS number. Software like Adobe Photoshop can also use these numbers, so you’ll get what you expect.
If you need a specific Pantone color, be sure and let your printer know. There will be varying costs for color matching due to the increased level of accuracy required.
Variations in Substrate
There is one final reason colors will vary, which is the surface you’re printing on. The substrate, or material on which the ink is placed, can make a difference in how the color is represented. For example, ink on a vinyl banner lays on the surface, resulting in more vibrant color. Fabric, on the other hand, absorbs the ink, resulting in more muted colors. This will cause deep saturated colors to look a little lighter. The identical digital file, with the identical color profile, will look very different on a vinyl compared to fabric.
The same is true if you print on coated versus uncoated paper. The ink on coated paper sits on the surface, resulting in more saturated color. Ink on uncoated paper, on the other hand, gets absorbed into the paper, muting the colors a bit. Also, the glossy shine on coated paper makes whites look brighter compared to uncoated paper. So again, the identical digital file will have a slightly different appearance on coated and uncoated paper stocks.
If you are concerned with the color of your print resource, speak with a print specialist to determine if the stock you are choosing will give you the desired result.