No spot colours used
This check makes sure that all inks in the document are set up as [Black] or spot colours and are not using Cyan, Magenta and Yellow inks.
‘Process Colours’ are the Cyan, Magenta, Yellow and Black inks used in the CMYK print process.
While the vast majority of commercial print jobs are printed in CMYK, some workflows use different combinations of inks e.g. just two inks (duotone) or just three inks (tritone).
The use of limited spot colour inks, typically PANTONE inks, can give different design options and challenges and alter the cost of production and it is advised to check with production before using spot colours.
Typically, when producing a book with a limit number of spot inks, the Cyan, Magenta and Yellow plates are not required. This check will flag any use of CMY inks.
A spot colour is shown in the InDesign swatches panel with a small circle (a spot!) to the right of their name in the list of Swatches used in the document.
