What Is CMYK in four colour printing?

CMYK is the colour profile used for four colour printing, it stands for cyan, magenta, yellow and black. CMYK is the industry standard for colour printing across the world for digital and offset printing methods.

The first use of CMYK in printing dates back to 1906 by the Eagle Printing Ink Company. They invented the CMYK process with the wet inks, cyan, magenta, yellow and black – CMYK. All four of these colours can be combined to create almost an unlimited number of colours.

C = Cyan

Cyan is synonymous with the colours; aqua, teal, electric blue and turquoise. Cyan got its name from the ancient Greek word Kyanos meaning ‘dark blue’ ‘dark blue enamel’. 

M = Magenta

Magenta is a colour defined as a pinky purple / red colour. It is one of the main colours of the CMYK printing process. It got its name from François-Emmanuel Verguin, a French chemist who originally called the Magenta colour – fuchsine.

To find out more about the colour Magenta visit here.

Y = Yellow

Yellow in the four colour printing process is the brightest of all the colours. It is a very bright shade of yellow and helps to brighten certain tones.

Yellow is synonymous with the colours;

K = Black

Black is as it sounds, a pur black toner used to produced black and halftones.

We have to have a separate black toner because when we use CMY alone it does not create a black but a very dark shade of brown. 

When you use all 100% of each colour you create a solid black and when you use 0% of the colours you will create a white as all the colour has been removed.

If you want to have a black and white print, you can achieve this by using only the black but it will not be as ‘deep’. If you are trying to create vibrant tones or rich blacks then you will need to include CMY. Usually 50% C, 50% M, 50% Y and 100% K.

This process is used for all single print colors. You can achieve the colour you want by using a single colour but you will have a better effect using multiple colours like you would with the rich black.

The digital printing methods we use for all our colour printing use CMYK. Our Ricoh 9200, the main colour printer, uses CMYK to print outstanding image quality comparable to offset printing.


RGB stands for Red, Green and Blue and they are the primary colours from which all other colours are made from.

R = Red

G = Green

B = Blue

With CMYK printing when all the colours are added together you will get a very rich black, whereas with RGB, when the colours are combined you will get a white.

This is because CMYK printing is a subtractive process and RGB is an additive process. If you want to achieve a black with RGB then you will need to subtract all the colours instead of adding them.

CMYK and RGB are both used very differently depending on the medium in which they are intended for. CMYK is used for printing and RGB is used for digital purposes.

RGB is not used for printing and is a process that is used for many electronic screens. This is why it is very important to have any documents that are going to be printed in CMYK.

CMYK in Digital Printing

A digital monitor acts as your background but instead of being white it starts off as being black. So when we want to create a colour on a digital screen we need to add light to it. That is where the additive properties of RGB come in. The monitor is comprised of 3 tiny lights (RGB) inside a single pixel and when we light up the lights with certain RGB values we get the certain colour in the pixel. When you have a digital screen with millions of pixels you get the desired image.

With CMYK printing the background is already white and so when we want to create a colour on our white background we simply add the desired colours. If we want to create a certain colour value or a certain shade, we have different values of our individual CMYK colours to add. The more we add, the higher the individual values, the darker the colour will get.

Unfortunately, the colour range of CMYK is less than RGB and so you are not able to get as many vibrant colours like RGB. CMYK has a numerical range of 4 x 100 and RGB has a numerical range of 3 x 256.

The number one design rule for creating your document that will be printed is to design it using the CMYK colour profile. Designing your document in CMYK ensures that you will have accurate reproduction of colours when your document is printed.

If you want more information on printing visit our helpful printing FAQ

Click here if you would like a book printing quote.