It’s hard to believe that over thirty years have passed since the first issuance of United States Plate Number Coils (PNC’s). These issues were created by the printing of the plate number on each roll of the plate. Most are very common; some are very scarce. However, they are legitimately made varieties, not issued for philatelists and having a provenance similar to plate number blocks and coil line pairs, both of which specialties have been part of mainstream US collecting for nearly a century. But PNC’s have had the misfortune to be issued too late, after the period that philatelists take hard core specialization seriously, and so have been relegated to second class status when by all the traditional philatelic markers they should enjoy wide popularity.
WWII is more or less the break off on where philatelists do their most detailed specialization. For most countries, the US included, issues before 1940 are subject to far greater specialized scrutiny than issues that come later. This has occurred because earlier collectors had far fewer stamps to collect and so studied their stamps to a far greater degree than stamps are studied and collected today. Perforation varieties, which on earlier US stamps are listed as separate, major catalog numbers, are on more modern issues relegated to minor “a” number status. As such they listed in footnotes, or not even notated at all. Paper varieties such as the Silkcoat of the 2