Editing Overprint (section)

== Precancels ==
{{main|Precancel}}
Any stamp that is cancelled by postal authorities before it is sold is described as "precancelled":<ref>Reinfeld, p.37.</ref> the precancellation mark is an overprint. This is usually only done when stamps are sold in large bulk quantities to businesses or other large organizations: the postal service will save the labor of cancelling each individual stamp by  precancelling the entire purchased quantity.<ref>Williams & Williams, p. 257.</ref> The overprints also help prevent theft or misuse because they usually include the name of the city or region in which they are to be used. Unlike standard cancellation marks, they usually do not give a specific date, affording the bulk purchaser time to use them at their discretion. In some situations, however, months or years may be included in the overprint to indicate an expiration.

Precancels for official government use are fastidiously prepared, but other kinds are almost always "heavy cancels" which deliberately obliterate much of a stamp's design.

Since the 1980s, many modern postal systems no longer use overprints to indicate bulk purchases. Bulk mail is [[Franking#Postage (stamps, etc)|franked]] using [[barcode]]s on pre-printed envelopes or on blank [[adhesive label]]s. The [[USPS]] introduced a [[Intelligent Mail barcode|new standard of barcode cancellation]] in 2011.
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File:StampCanadaPréoBarVictoria1870-T35i.png|[[Postage stamps and postal history of Canada|Canada]], 1870: Early heavy cancel for bulk purchase
File:Franceprecancel5cparis1920.jpg|[[Postage stamps and postal history of France|France]], 1920: Bulk postage precancel marked for [[Paris]]
File:Stamp US 1938 2c precancel.jpg|[[Postage stamps and postal history of the United States|United States]], 1938: Business precancel marked for [[New York City]].
</gallery>