Converting an RGB image to CMYK using Photoshop
Photoshop allows you to edit your images in either RGB or CMYK "color spaces". When we generate light and color using a computer monitor, we use a combination of Red, Green and Blue (called "RGB") dots. When we print color images light is reflected off the image (not generated like a monitor does) and so a different set of colors are used. Printing presses use Cyan, Magenta, Yellow and Black (called "CMYK"). This is a "4-color process" that makes up the majority of printed material you see each day. If you're going to use your image on a website, you can work in RGB exclusively, but if you plan to print your final work, your RGB file must be converted to CMYK.
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