Determining Coil Plate Numbers Before 1980

Before the transportation series when plate numbers did not routinely appear on stamps (Cottrell press?), how did Durland, or anyone for that matter, determine the numbers of the plates used? I have seen miscut coils that reveal partial plate numbers. Were miscuts so common that with searching one could determine all the plates used? I assume many rows of coils stamps were printed adjacent, and the plate number only at the bottom or top row of stamps, so to happen upon a plate number you'd have to get a miscut from the bottom or top row, no?

Each plate has its own distinct details. Usually an experience and knowledgeable philatelist can look for certain characteristics that made each plate unique. Kind of like fingerprinting.

I am not sure what you mean by miscut, but certainly identifying a single as a opposed to a full sheet would be more difficult.

Of course the plate numbers make identification much easier.

I believe miscuts are one way to determine what plate numbers were used. Maybe there are reports generated by the printers that also have that information. The United States Specialist lists newly discovered plate numbers in each issue of the journal. These lists are used to update Durland. It seems to me each issue contains at least one plate number update for classic era stamps.

Robert

In the era you ask about, the US Specialist regularly had a regular column listing the BEP plates certified, when they went to press, when they were canceled, and the total impressions made. And yes, most of the coil plates are soon discovered through mis-cut examples.

Miscut:


Yes. it's the discovered and decipherable miscuts that confirm the plate numbers given in Durland. They were being looked for way back when, but remember they were dealing with post office rolls of 1000(correct number?). Note the numbers would be next to the line, so they were easy to check for in a roll that looked off-center when coils had lines.

As John Becker states, before 1981 the BEP would regularly list which plates were sent to press. That is Durlands main source of the coil plates. Even after the first "plate numbers" were printed on the stamps, the real Plate numbers were listed by the BEP.
The "plate numbers" that you find printed on the stamps were not the official plate numbers.

Peter

Just to clarify, pre-1981 they were real plate numbers (sequentially incremented), after 1981 they were psuedo plate numbers starting with #1 for the first plate used for each color for each issue.