BLACK AND RICH BLACK
The two colours might look identical on screens, but in print there will be a difference in colour, and each has their own purpose. Standard black is used for text and fine lines. Rich black is used for large text, and all images in full colour printing.
Rich black is an ink mixture of solid black over one or more of the other CMYK colours, resulting in a darker tone than black ink alone generates in a printing process.
Usage of Black in Artwork
Fine Black Lines & Text
We recommend that fine black text & lines are set to: C=0%, M=0%, Y=0%, K=100%. Where possible, such text & lines should also be set to overprint.
For a full rich black we recommend you use the combination of: C=50%, M=50%, Y=50%, K=100%. Rich black should only be used for areas 30mm square or larger, excluding text. These areas should not be set to overprint.