ISO 18621-11 implementationISO 18621-11 Graphic Technology - Image quality evaluation methods for printed matter - Part 11: Colour gamut analysis describes methods of analysing and comparing the gamuts of colour prints. In Annex A it describes example test charts in RGB and CMYK which can be used in the analysis and volume calculation procedure described in the body of the standard.
Alternate test charts
An alternate patch set based on CMYK gamut boundary colours has been derived. The chart has 382 faces on the gamut surface. This patch set has been shown to give a gamut volume that is a close match to the reference values in Annex B when computed according to the method in ISO 18621-11.
The CMYK coordinates of the faces are given in this spreadsheet. This set of CMYK coordinates is present in a number of standard test charts used for printer characterizations:
Errata in ISO 18621-11:2020
Users of ISO 18621-11:2020 should be aware of two issues in the published standard.