However, we understand that for clients, this technical language might result confusing at times and, quite often, we have found that even among people with years of experience in the printing and advertising industry, very few know why a specific color mode is a standard.
In essence, CMYK and RGB are the two most common methods of creating color. CMYK stands for cyan, magenta, yellow, and black. That “k” for black comes from the printing press days when the printing process involved the use of plates and the black plate was called “key”. On the other hand, RGB letters represent red, green and blue colors.
Additive vs Subtractive
The most basic need-to-know aspect regarding color models is that RGB is meant to be used for digital environments and communications, and CMYK is best suitable for printing. However, a deeper look into the color creation will introduce more technical concepts and terms, such as “additive” and “subtractive” to differentiate between RGB and CMYK respectively.
In the context of color models, it might be confusing to just say “additive” or “subtractive” without mentioning what is being added or taken, and in relation to what. In simple terms, these concepts relate to perceived light and describe how the models interact to form visible colors.
RGB is an additive color scheme. What that means is that it combines the primary colors red, green and blue, and by changing and varying the degree of each color, you can create others. When combined to their full extent, the result is pure white, and when combined to the lowest value, the result is perceived as black.
To understand RGB better it might be useful to think about your television or your computer monitor. In them, the image is created by pixels and if you could take a magnifying glass and see each pixel individually, you will find one of those three colors. The light is projected through the pixels and blends on the eye’s retina to form a color image. When no light is being projected (when the screen is off, for example), then we perceive black.
In the other end, CMYK is called subtractive because the model starts from white (no color) and other colors are created by subtracting white with pigments and dyes. These pigments, when printed onto paper create the desired image. CMYK is not based on colored light, but colored ink instead.
The difference between colors on your monitor and the colors on print.
In theory, RGB has a larger color gamut than CMYK. That is why RBG works better for monitors and screens since it can display about a million more colors than what can be achieved with printing. Nonetheless, that does not mean that some colors cannot be printed, they just need complicated processes like paper treatments or additional colors of ink.
Due to the differences in color ranges between RGB and CMYK is very common that some colors appear different between monitor and print. However, to minimize error and achieve a very close match, the best option when designing something that will be printed, is to set the color mode in the software to CMYK. Although a design made in RGB can also be later converted to CMYK, some colors may suffer variations during that process since there is no perfect correlation between the two color models.
In addition, it is also important to be aware that even when specifying the same CMYK values, a print might look different depending on the paper used to print, since the color of the paper and the way that light hits the material affect the result.
RGB for digital, CMYK for prints.
For the record, neither system of color is able to reproduce all colors in nature, but both offer good enough approximates, and to visually and effectively communicate with audiences, all the technical stuff is unnecessary at the end of the day. However, sending a file to the print in RGB might delay your order and your colors will not be as similar as you might like to your artwork, so please be careful.