CMYK vs RGB

Unsure whether to use CMYK or RGB for print? Mixam is here to give you answers so you can create projects in incredible colour.
 

RGB Colour profiles

RGB has three primary colours of light: Red, Green, and Blue. Electronic devices like computers and tablets combine these three colours to produce all other colours on a screen.

The RGB colour gamut (i.e. the range of colours within a colour spectrum) has a broad range of colours because it essentially mirrors how our eyes see colour. Our retinas receive red, green and blue light, which is then processed in the brain and allows us to see an array of colours.

Of course, this all depends on one key factor: light. Printed matter doesn't generate light - it reflects it. So how do you reproduce colour in print if with no light source? The answer is you need to subtract colour, which is where CMYK comes into play.

The RGB colour model

 

RGB is an additive colour profile because you create new colours by adding primary colours of light together:

Green light + Blue light = Cyan 
Blue light + Red light = Magenta 
Red light + Green light = Yellow 
Red light + Green light + Blue light = White

 

CMYK Colour Profiles

CMYK stands for Cyan, Magenta, Yellow and Black (the K stands for Key). Unlike RGB, where you create colours by adding two or more together, CMYK is a subtractive colour profile, so you remove a primary colour of light from any white light that hits it.

Imagine you have a piece of white paper - it's white because it reflects every wavelength of light. Using Cyan, Magenta and Yellow in different proportions, you subtract specific colours of light to produce a wide range of colours.

You should get Black by combining Cyan, Magenta and Yellow. But our eyes perceive colour the RGB way, meaning CMY doesn't produce a perfect result. To combat this, we add black ink. It will absorb all light and provide darker tones and richer blacks.

White light, like daylight, appears visible to the naked eye, but it's not void of colour. White light occurs when all colours in the visible spectrum appear in roughly equal amounts. By altering these amounts, we can subtract wavelengths and produce different colours:

The CMYK colour model
  • Cyan ink reflects Green and Blue light - but not Red
  • Magenta ink reflects Blue and Red light - but not Green
  • Yellow ink reflects Red and Green light - but not Blue

To produce the three primary colours, you have to think in reverse:

  • Cyan and Magenta combined only reflects Blue light
  • Magenta and Yellow combined only reflects Red light
  • Yellow and Cyan combined only reflects Green light
 

How to Convert RGB to CMYK

CMYK is a subtractive colour model, meaning its colour range is more limited than that of the additive RGB model. As a result, RGB colours may appear less vibrant when converted to CMYK.

The image opposite shows various RGB profiles' colour ranges (gamuts) compared to CMYK. You cannot accurately reproduce colours outside the CMYK gamut or high contrasting or 'neon' colours in print. As indicated in the image, the CMYK gamut is much more restrictive than RGB.

To ensure your colours stay within the printable range, download and install our preferred CMYK profile here.

Our platform automatically converts any RGB files you upload to CMYK. While our conversion system is accurate, we recommend manually creating your designs in CMYK to achieve the best results.

How to convert RGB to CMYK with a colour wheel gamut illustration.
 

What Is a Colour Gamut?

Gamut refers to the complete range or scope of something. For colour reproduction, a colour gamut describes the subset of colours available for print.

To ensure colours stay within the CMYK colour spectrum, if you design your artwork in programs like Adobe PhotoshopInDesign or Illustrator, any colours detected outside the range will prompt an out-of-gamut pop-up warning in your Colour Picker tool. It appears as a triangle with an exclamation mark and will inform you that your chosen colour may not print accurately in CMYK. Your design program may suggest a similar colour to apply within the spectrum. Or, you can reference our list of recommended CMYK colour values to ensure colour consistency.

Out of gamut warning in Adobe creative tools
 

Working With RGB and CMYK Profiles

Everything printed on paper will have a CMYK ink colour profile. And anything created for on-screen viewing will have an RGB colour profile. But you should make and print your designs in CMYK.

However, if you created a webcomic, you would design it in RGB for better web viewing. If you want to print your webcomic, you need to convert your artwork files to CMYK and manually adjust any colours that may not look right. Creating artwork in CMYK for online projects can restrict the creative process due to limited colours.

To get an idea of how your RGB project will appear in CMYK, switch to CMYK Mode in Photoshop or InDesign. Then you can easily see which colours may need adjusting.

If colour accuracy is vital to your project, you can order one copy to see how your final prints can look. If you have any questions, contact our team of print experts via email, phone, or in the Messages tab of your pending orders - we're always here to help.

 

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