Life can be a series of ups and downs, and instituting a process control system can follow the same zig-zag pattern, but with one important difference: With process control there are a lot more ups than downs.
First the good news: having automated process control on press has never been as inexpensive and easy to implement as it is now. Clear standards and methodologies exist, proofing is better than ever, and true automated spectral scanning is now available for a fraction of the price that crude density-only systems cost only a few years ago.
Now the bad news: Once you start scanning full-width color bars on all your press runs, with graphic display of primary and overprint L*a*b* data, TVI or Dot Gain, gamut volume and gray balance, you are liable to discover that your press may not performing as well as you thought it was, and maintaining adherence to standards seems to be near-impossible.
Finally, the really good news: The data gathered with regular scanning of press sheets makes it easy to diagnose and quickly solve long-standing problems that had been costing you thousands of dollars, and get back on track for radically reduced make-ready times.
A client recently went through the up-down-up process and is now thrilled with the improved results and reduced costs he is experiencing. Starting from the usual outdated densitometer-plus-eyeball method, he switched to full sheet spectral scanning. The results were immediate and impressive, but he soon began to notice problems he had been unaware of: the dot gains were unpredictable, yellow was frequently contaminated, and deltaE’s on overprints were unacceptably high.
Armed with detailed reports from his scanned press sheets, he called in his ink and chemical suppliers for help. They found problems with ink tack sets, an improperly calibrated fountain mixture pump, and defective Ph and conductivity sensors. None of the problems were expensive or difficult to fix, yet they had been contributing to large and unnecessary costs in terms of make-ready time, paper waste and lost opportunity for months or even years, and yet there has been no awareness of these problems until he began regularly measuring every press run.
With hidden problems uncovered and fixed, quality is up and costs are down, and it was made possible by putting a little bit of bad news to good use in a process control improvement program.