Cancellation
A machine cancellation
A cancellation must be distinguished from other postal markings, such as postmaster's provisionals, marks, generally from the pre-stamp period, to indicate prepayment of postage.
A pen cancellation
Stamp collectors like to see stamps which are either 'lightly cancelled' or which have 'bulls-eye cancellations'. Another phrase for 'bulls-eye cancellations' is 'socked on the nose,' the acronym for which is SON.
A lightly cancelled stamp would have the postmark on a corner or small portion of the stamp. As lightly cancelled stamps are in general more valuable than heavily-cancelled (exceptions, discussed below, may be bulls-eye cancellations and special or rare postmarks), collectors have at times rubber-stamped (or handwritten) "philatelic mail" or the like on their covers to get the postal clerk or mail processor to cancel the stamps lightly. (It was perhaps from concern that a conventional cancellation device would damage some of Tonga's early foil stamps that a rolling cancellation device was employed.)
A bulls-eye cancellation is a readable postmark which entirely or almost entirely is on the postage stamp. They are favored by stamp collectors because one can see the time, date, and location where the stamp was used.
In the early period of the issuance of postage stamps in the United States a number of patents were issued for cancelling devices or machines that increased (or were purported to increase) the difficulty of washing off and reusing postage stamps. These methods generally involved the scraping or cutting-away of part of the stamp, or perhaps punching a hole through its middle. (These forms of cancellation must be distinguished from perfins, a series of small holes punched in stamps, typically by private companies as an anti-theft device.)
Cancellations may either be applied by hand or machine In addition to everyday cancellations there are pictorial cancellations, which as the name suggests contain pictures or images associated with the commemoration of an event or anniversary. Some people attempt to use stamps relating to the theme of a pictorial cancellation on the envelope [1]. First day of issue of a stamp or piece of postal stationery is another type of cancellation.
In the United States, while cancellations are nearly universally applied by the authority of the United States Postal Service, it is legally possible to use one's own cancellations on a letter bearing United States postage stamps — if the letter is delivered by the sender, its employee (in the case of a company) or by a private delivery service following the requirements of the "Private Express Statutes". Private cancellations have actually been used in Germany. Private cancellations are to be distinguished from private overprints.
See: numismatics
