What is RGB & CMYK?

RGB is used for digital artwork, and refers to the primary colours of light, Red, Green and Blue. This is the way that monitors, television screens, digital cameras and scanners all create images.

CMYK is used for printed artwork, and refers to the primary colours of pigment: Cyan, Magenta, Yellow, and Black*. These are the inks used on the press in '4-colour process printing'.

Why does this matter?

Both RGB & CMYK handle colour differently - the combination of RGB light creates white, while the combination of all CMYK inks creates black. Therefore, the colours you see when creating artwork on you computer are impossible to reproduce exactly on the printing press.

What if I use the wrong colour space in my artwork?

If you use the wrong colour space for artwork (i.e. a CMYK file for digital artwork) there will be a colour shift when you see it on screen (i.e. on a website). Colours may appear a different hue, turquoises more green, and bright oranges much darker.

How to convert colour spaces:

Converting colour spaces is quick and straightforward:

To do this in Illustrator:

• In the Menu Bar go to File > Document color mode > and select either RGB color or CMYK color.

To do this in Photoshop:

• In the Menu Bar go to Image > Mode > Choose RGB Colour from the dropdown list.

For more information on converting files in other applications click here.

*Why is Black 'K' in CMYK?

'K' stands for 'key', as the black ink plate in four-colour printing was called the 'key' or 'keyline'.