In this section you will learn about what "Gamut" actually is and why it is important when creating digital art to be printed. Photoshop CS3 is the program being used for this tutorial. First a little background on color modes. "RGB" is the term describing an additive color model in which red, green, and blue are added together to create a wide range of colors. "CMYK" is a four color process using Cyan, Magenta, Yellow and Black. This is a subtractive color model in which the inks are normally printed onto a white background and therefore take away some of the brightness from the white. For example: 100% Red, 100% Green, and 100% Blue create White. 100% Cyan, 100% Magenta, 100% Yellow, and 100% Black create a rich deep Black. Being that RGB creates a display using three colors and CMYK uses four colors, there is a large amount of colors that are "out of gamut", and should be watched out for when designing with the intent to print. These colors may be in the RGB spectrum, but not in the CMYK. What happens is this, the RGB image may look correct until it gets printed using CMYK. The colors in RGB may look bright, vibrant or even neon, and when they are printed they usually appear darker and duller than what you see on the screen. This image shows the colors that a typical computer monitor (CRT) can display. The gray areas are colors that fall outside the spectrum of RGB (Red, Green, Blue). When printing, the colors outside of the viewable spectrum are very important. When dealing with CMYK printing and viewing on an RGB display, many things can happen. You can create an image exactly the way you want it only to get the end result back and it's not what you wanted at all. If you are a professional, this can make for some unhappy customers. Some printing companies request that all graphics you send them be in RGB format, but be using CMYK colors. Not only can this be confusing, but can also create obstacles. When editing your images in photoshop, it is always a good idea to convert your image to CMYK just to verify your colors are within range and will print as you see them on your screen. A good rule to follow is to avoid the extreme colors like neons, and other colors generally not found in nature. Some filters do not work when using CMYK, that is fine, you can convert it back to RGB using the following: Image > Mode > RGB then Image > Mode > CMYK to convert it back. As a way to see if your color is out of Gamut, you can turn the Gamut warning on by following these steps: View > Gamut Warning. There will be a check mark next to it if you have it activated. What that does is this, when you are working on an image and you have it in RGB mode you can view which colors will not print correctly as they will be grayed out in the image. It is what it says, simply a warning. The design will not print with the gray warning over it. It is just showing you that it will not print the way you want it to unless you correct it. Another type of printing process is called the Pantone Matching System. The PMS system uses a term called "spot colors", and uses swatch books provided exclusively from Pantone. The display on your computer and the ink is specifically formulated to match precisely. There should be no color variation. When a printing press offers and prefers this option you should design with its settings.