Plate block
Encyclopedia
A plate block is a block of stamps from the edge of the sheet which shows the plate or cylinder from which the stamps were printed.
In some cases, for instance the Penny Red
s of Great Britain
and modern United States
plate number coil
s, the plate numbers appear in the stamps themselves, but the more common practice is to include the number in the margin of each sheet, sometimes alongside the name of the printer.
On coil stamp
s (stamps issued in a long band of single stamps with the edges imperforate
) a plate number sometimes is printed on the margin of a stamp, which collectors refer to as a plate number coil
. Mint plate number coil stamps are most often collected as strips of three or five with the stamp with the plate number at the center of the strip.
Then plate block collecting changed in the US due to the addition of up to eight multi-digit numbers which represented different colors used to print the stamps. The numbers were printed along the selvage. This meant collectors needed many more stamps to save a single plate block. This lasted for about ten years before the post office reverted to the traditional single number for most stamps. In a press release dated Dec. 10, 1980, the postal service announced a new plate numbering system that would, except in cases where more than four designs appear on a pane, "establish a plate block as consisting of four stamps regardless of the number of inks used or the press used to print the stamps." Now, new issues often begin with a number such as "11111," with each digit in a different color. Stamps printed in large quantities may have multiple plate numbers so the next plate combination might be identified as "22222" and so on.
s will list these. They may also collect all of the block positions, such as the numbers of each corner that exist after a large sheet is quartered.
Background
The numbering of printing plates has long been a part of quality control in the printing process. That way, if someone at the printing plant notices a problem with the printing of a certain stamp, the plate number can be used to locate the proper plate or cylinder so the problem can be investigated.In some cases, for instance the Penny Red
Penny Red
The Penny Red was a British postage stamp, issued in 1841. It succeeded the Penny Black and continued as the main type of postage stamp in the United Kingdom of Great Britain and Ireland until 1879, with only minor changes to the design during that time...
s of Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
and modern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
plate number coil
Plate number coil
A plate number coil is a United States postage stamp with the number of the printing plate or plates printed on it. The plate number typically appears as one or more small digits in the margin at the bottom of the stamp. The plate number may be centered or, on some coil issues, located toward the...
s, the plate numbers appear in the stamps themselves, but the more common practice is to include the number in the margin of each sheet, sometimes alongside the name of the printer.
On coil stamp
Coil stamp
A coil stamp is a type of postage stamp sold in strips one stamp wide. The name derives from the usual handling of long strips, which is to coil them into rolls, in a manner reminiscent of adhesive tape rolls...
s (stamps issued in a long band of single stamps with the edges imperforate
Perforation
A perforation is a small hole in a thin material or web. There is usually more than one perforation in an organized fashion, where all of the holes are called a perforation...
) a plate number sometimes is printed on the margin of a stamp, which collectors refer to as a plate number coil
Plate number coil
A plate number coil is a United States postage stamp with the number of the printing plate or plates printed on it. The plate number typically appears as one or more small digits in the margin at the bottom of the stamp. The plate number may be centered or, on some coil issues, located toward the...
. Mint plate number coil stamps are most often collected as strips of three or five with the stamp with the plate number at the center of the strip.
In the United Kingdom
In the U.K. plate blocks are also commonly known as cylinder blocks and are widely collected as they still form an important part of the printing of current British stamps.In the United States
Until the late 1960s, United States stamps included two rows of stamps attached to one another in a block of four or more, with printing information, including the printing plate number, on attached margin paper. A number is used to identify one specific plate or cylinder used to print the stamps.Then plate block collecting changed in the US due to the addition of up to eight multi-digit numbers which represented different colors used to print the stamps. The numbers were printed along the selvage. This meant collectors needed many more stamps to save a single plate block. This lasted for about ten years before the post office reverted to the traditional single number for most stamps. In a press release dated Dec. 10, 1980, the postal service announced a new plate numbering system that would, except in cases where more than four designs appear on a pane, "establish a plate block as consisting of four stamps regardless of the number of inks used or the press used to print the stamps." Now, new issues often begin with a number such as "11111," with each digit in a different color. Stamps printed in large quantities may have multiple plate numbers so the next plate combination might be identified as "22222" and so on.
Collecting
The usual practice in plate block collecting varies by country and era; the classic 20th century US plate block consisted of a 2x2 block in the corner of the sheet for rotary press issues (a 2x3 block in the midddle top, bottom and/or sides of the sheet for flat plate issues). Ambitious collectors will seek to own blocks displaying every known plate number for the stamp; specialized stamp catalogStamp catalog
A stamp catalog is a catalog of postage stamp types with descriptions and prices.The stamp catalog is an essential tool of philately and stamp collecting...
s will list these. They may also collect all of the block positions, such as the numbers of each corner that exist after a large sheet is quartered.