The term “colour scale” has two meanings in the printing industry:
1. standardised printing colours (process colours) for four-colour printing (CMYK), e.g. the Euroscale.
2. proof scale: A schematic ink sample that is produced during a press proof and serves as a basis for the customer’s assessment of the printing failure and as a binding template for correct colour guidance in the production run.
In four-colour printing, for example, such a scale consists of one single print each in cyan (C), magenta (M), yellow (Y) and black (K), as well as three different combined prints in which first two, then three and then all four colours are printed together.