When submitting graphic designs to any printing company, you will often find that one of the requirements is to submit it using the CMYK color model. What exactly does this mean?
There are two common color models used: CMYK (stands for Cyan, Magenta, Yellow, and Black) which is used for anything printed and RGB (stands for Red, Green, and Blue) which is used for digital media like computer screens and televisions. Why is this the case?
Additive versus Subtractive:
Basically, it all depends on how light is used to create a certain color. RGB is an additive color, which means the more light is emitted, the lighter the color will be. CMYK is a subtractive color, meaning the more light is absorbed, the darker the color will be. The color you see on your computer screen is created by emitting light, while color on print (using ink) is created by absorbing light. Essentially, since the ink does not emit light, the colors you see on your computer screen will behave differently once printed on paper.
Also, your computer screen in RGB will have a wider spectrum of colors compared to CMYK. The limitation in color range between the two systems is very evident in bright, vibrant colors. The colors that you can get on a computer screen appear brighter and more vibrant because the screen emits light – the ink that you have on printed material does not.
RGB vs. CMYK in Printing
So why don’t we just use RGB inks in printing? Ink does not emit light when printed, which means that when you mix two RGB colors (which are already dark, to begin with), the resulting color is darker because the two colors will block each other. This makes it impossible to create light colors like yellow. On the other hand, CMYK colors are created by overlapping two of the primary RGB colors. Blue and green make Cyan, red and blue make Magenta, and green and red make Yellow. When you combine these overlapping colors, you can start subtracting lightwaves to get the color you want. For instance, if you mix Magenta (red and blue) and yellow (red and yellow), the Cyan color which is red and blue are being absorbed (subtracted) and you are left with the Red.
What does this mean to you? If you were designing a logo, flyer, or poster, using the right color system will determine how closely the printout will resemble the colors on your screen. Printing RGB files on a CMYK printer will not drastically alter your colors, but the mismatch is noticeable – like with Blue looking more like Purple, and Green being dull.
Converting your RGB file to CMYK before hitting the printers can be tedious. You won’t always get the exact color conversion, especially with Blues. To avoid any problems, for anything print, always start your design in CMYK color mode. This will give you the closest color match from monitor to print material. No system is perfect, so always leave room for some inconsistencies – even colors look different on different computer screens.