Rich black is a term given to the black colour that is produced by professional designers which does not appear grey.
When black ink is used in offset printing, it often appears grey, despite 100% black being used. Designers can add other printing colours to a black to make it known as ‘rich’ or ‘deep’ black.
How to Create Rich Black
The most popular choice is to use 100% black, as well as 40% cyan, 40% magenta and 40%yellow. A lot of people will not add the yellow percentage, however adding it can help to neutralise the hue.
Another choice is 60% cyan, 40% magenta, 40% yellow and 100% black. This will equal 240% and is the most that printers will not fuss about, adding more under colour can add problems on press.
Black Ink Overviews
Standard black 0C, 0M, 0Y, 100K
Rich black 63C, 52M, 51Y 100K
Cool black 60C, 0M, 0Y, 100K
Warm black 0C, 60M, 30Y, 100K
Registration black 100C, 100M, 100Y, 100K
‘Designer’ black 70C, 50M, 30Y, 100K
Rich black is known as being ‘blacker than black’ and although that is impossible from a colour theory point of view, it is visible in a printed piece. Using rich black and the visibility of it is based on a full understanding of inks, printing press and, in particular, the paper.
There are additional inks needed to form rich black, but this will obviously incur higher printing costs as a result.