| Color is something we experience every day, yet as a concept it can become very complex really fast: It is a component of light blended with our perception of light reflections off of objects. Instead of delving into a high-tech discussion about color and color theory, let's take a look at a couple of color and light concepts that designers and printers deal with all the time. Tip CRT and LCD monitors tend to render the same colors differently, which can make it difficult to match colors across monitors. If you use multiple monitors on your Mac or work in an agency with several workstations, try to stick with either all CRT or all LCD monitors instead of mixing them. Reflective vs. Transmissive Color Light is a critical component of color. Without light, we can't see any colors. The light we do see is always filtered in some way: It is filtered either as it reflects off of a medium or as it passes through some medium. Reflective color. You see reflective colors when light bounces off of objects. The cover of a book, the paint on a wall, and the clothes you wear all reflect light. The part of the light spectrum that different objects absorb doesn't get reflected back, which shifts the color to become what we perceive. Green grass, for example, absorbs and filters out certain parts of the visible light spectrum and reflects back the parts we see as green. Transmissive color. The colors you see when light is filtered through an object represent transmissive colors. Your Mac's display shows transmissive colors by filtering out different parts of the spectrum as light passes from the back of the display through to the front.
RGB vs. CMYK RGB and CMYK are color spaces we use every day in our design work-flow (Figure 5.1). One is based on transmissive color and the other on reflective color. Figure 5.1. The RGB color space (left) is transmissive, and it is how your Mac displays colors. The CMY color space (right) is reflective, and it's what lets you see objects around you. RGB. RGB, or red-green-blue, is a transmissive color space. It can display far more colors than CMYK, which is why an RGB image is more vibrant on your display than if you convert it to CMYK. Red, green, and blue are the primary colors, and are also referred to as additive primary colors because the combination of all three light colors produces white. CMYK. CMY, or cyan-magenta-yellow, is a reflective color space. Since this color space relies on imperfect pigments in the objects around us to reflect light, it can't show as many colors as the RGB color space. Cyan, magenta, and yellow are secondary colors, and are also called subtractive primary colors because the absence of all three produces white.
About the K in CMYK So where does the K come from in CMYK? The K stands for black. Over time, printers found that they could produce a deeper, more vibrant black on press by blending colors together to make the black we expect to see. Building black with equal parts of cyan, magenta, and yellow produces a true black, which is actually duller than the black we've grown accustomed to, and it's a little bit brown, too. To create the black we've come to know and love, they created an ink that has a deeper, richer color. In essence, it is "blacker" than true black. That's the K in CMYK. Using a black ink also has another benefit: cleaner and sharper text. If you had to rely on your print shop to build the black color for the text in your projects using cyan, magenta, and yellow, the letters could come out looking a little fuzzy, and they certainly wouldn't pop off the page. Also, if any of the press plates your print shop uses slip out of registration, your text gets blurry and very difficult to read. |
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