Your computer monitor displays colors in RGB (red, green, blue) format. The colors appear exceptionally brilliant, because they are being electronically illuminated. However, printing presses use the CMYK coloring format.
CYMK color schemes use four colors - Cyan, Magenta, Yellow, and Black, which when combined together can create any other color, but without the artificial illumination your monitor's screen provides
Whenever designing a brochure or other publication that will be sent to a professional printer, you must create your design in CMYK color AND the resulting pdf you send to the printing service must also be created using CMYK color. Details on switching to CMYK mode are provided in the software you use to create your design and to convert it to PDF format for the printing service.
Special Note for Using Black in Your Brochure
When choosing the color Black, for text or expanses of black color in your brochure - be sure to use only 100% black, not a mixture of cyan, magenta, yellow AND black.
100% black uses a CMYK value of:
C=0% M=0% Y=0% K=100%
Working this way is another step towards ensuring that what you see on your screen is what you will end up with in the final printed product and that you'll create a great, professional-looking brochure.
