Dampening water feeding method and printing machine

摘要

Densities of detecting patches also called control scales printed on prints in a first print job are used to control the feed rate of dampening water in a second print job following the first print job. Specifically, densities of detecting patches on the prints obtained from the first print job are measured, and a feed rate of dampening water is calculated from the densities of the detecting patches. A base feed rate of dampening water is calculated based on the feed rate calculated and a humidity and temperature occurring when the first print job is performed. A proper feed rate of dampening water is calculated based on the base feed rate and a humidity and temperature occurring when the second print job is performed.