A 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...

 error is any of several types of failure in the stamp printing process that results in stamps not having the intended appearance. Errors include use of the wrong colors, wrong denominations

Denomination (postage stamp)

:This article deals with the price of a postage stamp. For other meanings of the word 'denomination' see Denomination .In philately, the denomination is the "inscribed value of a stamp"...

, missing parts of the design, misplaced or inverted design elements, etc. The term "error" is typically reserved for obvious failures in the production process that (potentially) replicate over many stamps; unique errors or poor quality known as "freaks" or "oddities"

Errors, freaks, and oddities

In philately, "errors, freaks, and oddities" or "EFO" is a blanket term referring to all the kinds of things that can go wrong when producing postage stamps...

. Printing plate flaws, such as cracks, wear, or even constant flaws, and plate repairs, such as re-entries

Re-Entry

"Re-Entry" was the second album released by UK R&B / Hip Hop collective Big Brovaz. After the album was delayed in May 2006, the band finally release the follow-up to "Nu Flow" on 9 April 2007...

, are also not considered errors.

Genuine errors are uncommon or even rare; postal administrations have several layers of quality control and inspection, and most printing problems are addressed before the stamps ever reach the public. A particular error may only exist in a few dozen copies, and some well-known errors, such as the Treskilling Yellow, are unique (so far as we know). They are prized by collectors, with some fetching prices thousands of times higher than the normal stamp of their type.

Errors are known at every stage of production, starting from design, to engraving, to replication of the die, to printing itself, and to perforation. (In theory gumming errors are possible, in practice used stamps have no gum, so any error would become undetectable).
The largest run of an error on a postage stamp is the 2011 United States 'Forever Statue of Liberty Stamp

Forever Statue of Liberty Stamp

The United States Post Office issued the Statue of Liberty Forever stamp in December 2010. The stamp shows the replica of the Statue of Liberty in Las Vegas rather than the original Statue of Liberty in New York. The error was not noticed until March 2011. The error was identified by Sunipix, a...

'. The stamp shows the replica of the Statue of Liberty in Las Vegas rather than the original Statue of Liberty in New York. The stamp was released in December 2010 and the error was not noticed until March 2011. The error was identified by Sunipix, a stock photo agency in Texas. Ten and a half billion of the error stamps were produced.http://www.postalnewsblog.com/category/stamps/

The following is a list of the major types of errors.

• Design error
  Postage stamp design error
  A postage stamp design error is a mistake made during the design phase of the postage stamp production process. Design errors most commonly occur as minor mistakes, such as a missing letter in the binomial name of an organism depicted on the stamp, but some have been major gaffes, such as a map...
  
  : The picture may be of the wrong subject, maps may show wrong borders, the inscription may be factually wrong, text may be misspelled, etc.
• Value error or substituted subject: A die composed of multiple elements has the wrong elements mixed together, as for instance a low-value denomination being used on a design intended only for high values.
• Omission error: Part of the stamp's design is missing.
  • Missing color: Associated with printing processes which print the stamp in several different colors.
  • Missing overprint: A stamp valid for postage only when overprinted but with a missing overprint.
• Double impression: Stamp, or overprint, was printed twice, one impression offset from the other.
• Invert error: Part of the stamp is printed upside-down.
  • Inverted overprint
• Color error: Stamp is printed in the wrong color(s).
• Paper error: Stamp is printed on the wrong type of paper
  Postage stamp paper
  Postage stamp paper is the foundation or substrate of the postage stamp to which the ink for the stamp's design is applied to one side and the adhesive is applied to the other...
  
   which, e.g., may have a different watermark
  Watermark
  A watermark is a recognizable image or pattern in paper that appears as various shades of lightness/darkness when viewed by transmitted light , caused by thickness or density variations in the paper...
  
   or color than intended.
• Imperforate error: Perforations are missing on one or several sides, as perforations may be removed by cutting them off, imperforate errors are collected in pairs.

External links

• Errors on stamps
• Rick Miller, Errors versus errors, freaks and oddities
• Inverts National Postal Museum
  National Postal Museum
  The National Postal Museum, located opposite Union Station in Washington, D.C., USA, was established through joint agreement between the United States Postal Service and the Smithsonian Institution and opened in 1993. The museum is located across the street from Union Station, in the building that...
  
  
• Inverted Center Stamps