If you’re reading this post, chances are you have at least heard of or come across the acronym “CMYK.” Simply put, the letters stand for four colors: cyan, magenta, yellow, and black (though some would say the ‘K’ actually stands for the “key” color, which is almost always black). Printing presses blend these four colors of ink (by placing tiny little dots on paper) to make up just about any color the human eye can see.
So what does this mean for you? Well, if you are using Photoshop or Illustrator, or any other design program to create documents that will be printed on paper (as opposed to digitally, like on websites, for which you’ll use RGB color), you’ll need to make sure that CMYK color is what you are working with. Adobe InDesign defaults in CMYK color, so you usually won’t have to make any adjustments when creating a document using that program. But if you are using Photoshop, there is a good chance you’ll need to check and see if you’re using CMYK.
The process is quite simple, and you can convert to CMYK at any time while creating a project (so don’t worry if you’ve already been working on something for umpteen hours in RGB!) In Photoshop, simply go to Image > Mode > CMYK Color. You may get a pop-up that will ask you if you want to merge layers. I don’t usually recommend it, since that means you won’t be able to edit layers individually. But your colors might shift just a hair. But if you’re going to send something to a printer, you must use CMYK.