So what Are the Sources of Variability?
First, in order to use color management we need to characterize the proofing device. This involves printing a reference target, measuring the color printed for each patch, and then creating a color profile using this data. The first two sources of variability are:
1. Uncertainty in the colorimetric measurement of the printed reference target used to characterize the proofer.
2. The modeling errors in the proofer profile building process