COMPUTER-INTEGRATED MANUFACTURING -- Strategies for a "Smart Fa
Secondly, there is an entire series of measurement standards that apply to printing. These were among the first standards developed by CGATS (Committee on Graphic Arts Technical Standards), and they can serve as tutorials for how to use densitometers to control the printing process and spectrophotometers to match inks and, ultimately, images. Much of this early theory has evolved into practical, closed-loop color control for sheetfed and, now, webfed presses.
The machines are sophisticated, but they are measuring the same basic properties documented in the standards as the best way to control a press. Measuring the process is essential to a “smart factory.”
Thirdly, there is a series of standards that govern the process itself. The proper way to measure ink color and transparency “in the can” is defined in ISO 2846. There is also an ISO standard for platemaking, which helps define the reproduction argument (linear vs. bowed) that we are having with computer-to-plate. The “smart factory” of the future will properly define processes and establish shop standards based on good theory.
In an ideal world, each printed job should, at the very least, meet the customer’s expectation. In the real world, however, the printing variables noted above prevent printers and their customers from accurately and reliably predicting how the image will appear on-press.
Once the printing process is controlled, it can then be calibrated, and the output can be documented and related to the customer’s needs using the CGATS IT8 7/3 target and the ISO SCID images. And it is in this area of the process where most of the industry’s groups are involved.
There are already a multitude of standards, specifications and general guidelines that cover all of the various printing markets and products. On the theoretical side, ISO has a family of standards that define the measurement targets for offset (commercial and publication), newsprint, flexo, screen printing, gravure packaging and digital printing. These standards give representative aim points and process tolerance limits for each of these types of printing.