No matter what printing method you use, extremely high or low ink saturations of a single colour will rarely produce satisfactory results. Anything under 10% may not print at all, while anything over 90% may be impossible to differentiate from a solid colour. This problem is most frequent in black and white printing where only a single K colour from CMYK (Cyan, Magenta, Yellow, blacK) is used.
The K in CMYK actually stands for ‘Key’, but we will use the term blacK for simplicity. The Key plate is a metal plate that holds the detail in the image during the printing process. In CMYK printing this is done with black ink.
This grey line is easy to see on your computer screen. However, at just 8% saturation, 2% below the recommended minimum, it will be barely visible when printed. But if we increase the saturation to at least 10%, it will be more visible when printed.
On your screen, you can clearly see the small dark circle and the lighter circle that surrounds it. These are printed in black only.
However, when printed, the 91% saturation value of the lighter circle and the 100% saturation value of the darker circle will make them almost indistinguishable. So when printed, you would only see a single, dark circle.
This is because, while your computer screen uses light to produce colour (RGB), a printing press uses ink to produce colour (CMYK).
In addition, because the ink saturation of both shapes exceeds the recommended 90% limit, the whole area ends up darker when printed on paper than when viewed on your computer screen.
Ink saturation scale
We’ve covered the saturation scale for a single colour above. For example, if you’re printing in black and white, your only CMYK colour would be K (black). Ink saturation is also an important consideration when printing with all four CMYK colours.
When you are choosing CMYK colours for your design, they are formulated on a scale of 0% to 100%.
This isa measurement of how much of each C, M, Y, or K ink is used to create the final colour.
The more ink you add, the darker the final colour is.
So if each pixel in your print file has an ink saturation level between 0% and 100% and you have 4 CMYK colours, then the maximum possible saturation for each pixel is 400%.
For example, the blue/green colour we use for printing our Mixam logo is C:65 M:0 Y:28 K:0.
In other words, the Cyan is set at 65%, the Magenta at 0%, the Yellow at 28%, and the black at 0%.
That’s a total of 93% out of a possible 400%.
In the blocks of colour below, you can see how your monitor will show four different browns, ranging from 100% saturation to 400% saturation. You can see how they are created by increasing the percentage of each CMYK colour.
Once you exceed 250% saturation, the paper becomes heavily saturated with ink, which can increase printing costs and drying times due to the sheer volume of ink being used in the production process.
Best saturation level
In the same way that 91% blacK compared to 100% blacK looks different on a computer screen but will appear equally dark when printed, 300%CMYK saturation will also look equally dark as the 400% CMYK saturation when printed.
This is is why we recommend that even your darkest colour choices should stay within 150% to 250% total CMYK saturation.
This is the perfect range to keep the colours bright and fresh, without becoming muddy from all that extra ink.
Saturation works best when used sparingly. Even a deep, rich black can be incredibly vivid with less than 200% saturation. You just need to balance the overall CMYK values of your colours accordingly.
It’s also worth noting that some paper types will absorb more ink than others. Silk and gloss papers are the industry standard for crisp, clear printing. Uncoated and recycled papers are also available options, soak up ink more quickly, becoming much darker and possibly creating a bleed effect. The type of paper you want to use is an important consideration when setting saturation levels.