In philately

Philately

Philately is the study of stamps and postal history and other related items. Philately involves more than just stamp collecting, which does not necessarily involve the study of stamps. It is possible to be a philatelist without owning any stamps...

, a block is a group of postage stamp

Postage stamp

A postage stamp is a small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage. Typically, stamps are made from special paper, with a national designation and denomination on the face, and a gum adhesive on the reverse side...

s still attached to each other. Blocks are of interest not only because they are rarer than individual stamps, but they also preserve relative positions of stamps as they were originally printed, information that is crucial to understanding how the stamps were produced.

Format

Blocks of stamps from the edges of the original sheet or pane often include sections of the sheet's margin, which may have a wide variety of information. For instance, arrow blocks preserve the guide lines used by line up the sheets for perforation

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...

 or other production steps (these are usually angled in an arrow shape, thus the name), and center line blocks includes lines printed down the middle of a sheet. An imprint block includes the name of the printer, while for many United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 stamps the zip block includes a promotional mention of the ZIP code

ZIP Code

ZIP codes are a system of postal codes used by the United States Postal Service since 1963. The term ZIP, an acronym for Zone Improvement Plan, is properly written in capital letters and was chosen to suggest that the mail travels more efficiently, and therefore more quickly, when senders use the...

.

Collecting

The most commonly collected kind of block is the plate block

Plate block

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.-Background:The numbering of printing plates has long been a part of quality control in the printing process...

, which includes the part of the margin where the serial number

Serial number

A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...

s of the printing plates may be found.

Values

Although blocks of rare stamps are highly valued, a block's price may actually be so high that no buyers can be found, leaving the owner with the agonizing prospect of breaking up the block, so as to be able to sell the stamps individually. In some cases, dealers have publicized plans to break up a famous block, in the hopes of that someone will come forward to save the block from destruction.

See also

• Centro de hoja
  Centro de hoja
  Centro de hoja or Center of the sheet is a term used to describe certain Cuban postage stamps where there are intersecting gutters between four panes of stamps. The horizontal and vertical blank gutters divide the sheet into quadrants of 25 stamps each...
  
  , a center of the sheet block of stamps
• Plate block
  Plate block
  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.-Background:The numbering of printing plates has long been a part of quality control in the printing process...