ISO/TS 18621-21:2020

This document defines a measurement method for the evaluation of distortions in the macroscopic uniformity of printed areas that are oriented in the horizontal and vertical direction, such as streaks and bands.
It provides requirements for the layout of the test form, the use of a colour measurement device taking measurements in a 2D sampling grid, and the formula to compute the Macro-Uniformity-Score.
This document does not cover any non-adjacent or non-horizontal nor vertical patterns. Due to the used spatial frequency, the Macro-Uniformity-Score does not measure high frequency (fine) patterns such as missing nozzles.