Plate Number Coil

Plate number coils, otherwise known as PNCs, appear on the bottoms of certain stamps. A plate block number represents a single press printing. A single stamp series may contain several plate code numbers. (Each one of these numbers may represent a different color layer, for instance.) It may be difficult to read PNCs on old stamps, since they are typically printed in very small fonts.Plate number coils generally appear in one of several formats. One of the most popular is the PNC 5 format. This is a group of five ''post office fresh'' (mint) stamps, the middle stamp of which contains the plate number. Another format is the PNC 3. As with the PNC 5, the PNC 3 features its plate number on the center stamp. According to convention, PNC 3 stamps are not nearly as valuable as PNC 5s.There are also the ''PNSs'' (single plate number stamps). Before purchasing a PNS piece, you should scrutinize the find for any defects or smudges. Occasionally, a postmark or environmental damage makes the plate numbers on PNS stamps illegible. Many philatelists look for what are known as ''cover plate number coils.'' Basically, these are plate number stamps that have seen postal use.Given that there are over 400,000 varieties of stamps, catalogers estimate that there must be millions of varieties of plate number coils. Philatelists interested in PNC collecting often focus their efforts on a few series or even on a few kinds of stamps. Particularly for the big printings, (such as the Franklin one cent, which was minted in the U.S. between 1903 and 1905), it may be tough to gather fully complete PNC sets.