The problems we encountered on the 16 point PPV were probably due to the short runs for the test. On the the concentric test done on PPV substrate there was a "mottled" pattern on the Gracol 7 "gray area" almost as though the ink was emulsifying. I sent all of the test sheets to Mark Samworth for examination and he did come up with a series of PressSync curves to deal with the press gain, but was not completely satisfied that that screening technique would work on that substrate. We did not have any such problem using conventional or UV inks (Hostmann) on 20 pt SBS substrate tests, which all looked great. I would like to try more testing using the Concentric screening on a variety of plastic substrates using the new curves and longer runs, but right now I don't have a budget for it.
