ISO 20791:2021

Description

This document describes the procedures for evaluation of colour variation in the printing of photographic reflection colour prints. The following procedures are described to evaluate colour variation in printing within a consecutive print job, between several print jobs, or between multiple photographic images printed in different areas of a large sheet:

a) test targets for small and large photographic prints;

b) printing procedures and conditions;

c) sampling in correspondence to the production scale;

d) measurement of colour;

e) calculation and analysis of colour variation and

f) reporting.

The procedures presented in this document are applicable for prints with a size of available picture area ranging from 35¬†cm² (e.g. 5¬†cm¬†√ó¬†7¬†cm) to 5¬†400¬†cm² (e.g. 60¬†cm¬†√ó¬†90¬†cm). This document is applicable to any of the photographic printing technologies, including inkjet, thermal dye transfer, electrophotography and silver halide (chromogenic) technologies.