Precise On-Line Colour Measurement for Enhanced Press Performance, 2000 International Printing & Graphic Arts Conference Proceedings

Don Roworth--Colour quality control is increasingly a commercial necessity in printing. A real-time on-press colour monitoring system is an essential element in controlling colour without imposing high quality costs, but it must be sufficiently stable and accurate. A video-based system is described, able to monitor the colour of any selected areas of print at full press speed, in which special steps have been taken to ensure accuracy consistently on a par with a hand-held colorimeter. The system is designed to be easy to set up and run, tracks colour trends of each selected area throughout the print run, and flags to the printer any out-of-tolerance variation. At end of run, a colour conformity certificate may be printed. In addition to the confidence such a colour monitoring system gives to customers, it also brings tangible economic benefits to the press operation, and will form an essential basis for future technical advances.