Accuracy and Precision in Color Characterization

Several press tests have been performed by industry organizations and private companies to characterize the colorimetric output of various printing processes. Since most attempts have significant difficulty achieving targets and results are difficult to reproduce, characterization data from these tests are usually surrounded by controversy and met with hesitant acceptance. Analysis of the need for characterization data shows that: * Characterization data sets are critical for the implementation of digital imaging systems; * The foundation of good characterization data is a press test in statistical control relative to a solidly fingerprinted press output condition; and, * The quality of the characterization data itself is a function of the sampling plan which addresses test target configuration, test form configuration, press sheet selection and number of press tests. This paper defines the relationship between fingerprinting, process control and characterization, presents a survey of press tests that demonstrates the effect of sampling on press test repeatability and reproducibility and proposes methodology that could be used to resolve many difficulties commonly associated with many characterization data sets.