In this publication the recommendations of the CIE Division 2 "Physical Measurement of Light and Radiation" are given on the definition of geometries for the measurement of the colour of materials and the tolerances around those fundamental definitions that are required to provide an expected level of accuracy and reproducibility.

This publication documents, for the first time, definitive definitions of the geometric requirements for instrumental colour measurements. It further defines three levels of tolerances which will provide three ranges of accuracy and reproducibility so as to clearly define what is required for the highest level of inter-laboratory agreement and what will be acceptable for industrial or commercial applications of basic colorimetry.

The terms and symbols used in this report are intended to be consistent with the existing standards in the International Organisation for Standardisation (ISO) and in particular with ISO standards 5-1 and 5-4.