Have you ever posted a picture online and the colors suddenly seem way too bright? Or have you sent artwork to be printed but the print doesn't seem as bright it was on the screen? Then you have dealt first hand with the differences between RGB and CMYK.
RGB stands for Red, Green, and Blue, and represents the colors of light your computer monitor emits. Using varying intensities of each of these light colors can produce every color in the visible spectrum, but monitors can only display a certain range of them. With this in mind, RGB is the perfect mode for any designs that will be viewed on a screen, like websites and digital ads.
CMYK stands for Cyan, Magenta, Yellow, and Key, or Black. Key comes from the printing press days when the black plate was called the "key" plate since it carried the important key information related to the artistic detail. When it comes to physical printing, whether done on a press or digitally, cyan, magenta, yellow and black are layed down in layers of small dots to produce the different colors your eye will see. The range of colors it can produce is smaller than that of RGB, as you can see in the image below.
This is why you see a difference between the two. When you print an RGB image, the printer has to change the image to CMYK to process it correctly. This is why your colors may not seem as vibrant. Below is a great example of a side by side of an image in both modes.
Both images still look great, but the CMYK side is missing a few of the colors that make the RGB side more dynamic. This is why we always suggest that if you are sending over artwork for print that it is done in CMYK to be sure that you have a more accurate idea of how the finished product will look. We also have options for press checks and printed proofs so that you can really see how your final prints will look before you get a box full of business cards that you aren't happy with.
As always, if you have any questions or would like to know more about color options, please send us an email at firstname.lastname@example.org