Postmark

A postmark is an impression made by a postal authority on a stamp — and often on the surrounding envelope — that records the time, date, and location of posting. The word is sometimes used interchangeably with “cancellation,” but the two terms are distinct: a postmark specifically includes place and date information, while a cancellation is any mark that prevents a stamp from being reused. In practice most modern postmarks combine both functions, defacing the stamp while simultaneously recording the originating post office and date.

Types of Postmark

Circular Date Stamp (CDS) is the collector’s most prized type of postmark. A CDS consists of a circular impression bearing the name of the town or post office, the date, and often the time, arranged around a central void or decorative element. CDS strikes are applied by hand using a rubber or steel handstamp, which means their quality varies: a clean, well-struck CDS centred on the stamp is a genuinely attractive item, while an off-centre or faint CDS is far less desirable. For used classics, a fine CDS can significantly increase a stamp’s value compared to a heavy machine cancel.

Machine cancellations are applied mechanically as letters pass through high-speed sorting equipment. They typically consist of a series of parallel horizontal lines (the “killer bars”) striking across the stamp, with date and place information printed alongside. Machine cancels are efficient but rarely attractive; many classic stamps that would be visually appealing with a CDS are diminished by a heavy machine obliteration that obscures the design.

Slogan cancellations incorporate an advertising or public service message alongside the date portion — “Buy War Bonds,” “Post Early for Christmas,” or “Wash Your Hands” are classic examples. Slogan cancels are collected both for their philatelic interest and as historical artefacts documenting social campaigns and events.

Manuscript cancellations (hand-written pen cancels) were common in the earliest days of postal systems, when postmasters personally marked each letter. Pen-cancelled stamps from the classic era (pre-1880) are generally considered less desirable by condition-conscious collectors, though early manuscript cancels on entire (intact original envelope) can be historically significant.

Rubber handstamp cancellations are used in smaller post offices and rural areas where machine equipment is unavailable. These vary widely in quality and design.

Postmarks Versus Cancellations

The technical distinction matters for collectors: every postmark is a cancellation, but not every cancellation is a postmark. A stamp “cancelled to order” (CTO) — cancelled neatly by the issuing authority for sale to collectors without ever going through the post — is a cancellation but carries no true postmark recording a genuine mailing event. First day covers depend entirely on the postmark: the cancel must be dated on the official first day of issue and originate from an authorised post office to qualify as a genuine FDC.

Collector Value

Clear, light postmarks on used stamps are vastly preferred over heavy, smeared, or manuscript cancels. A well-struck CDS that does not obscure the stamp design represents the ideal for most collectors. Specialists in postal history seek unusual postmarks: ship postmarks (applied on ocean mail), railway post office (RPO) cancels applied on mail trains, and early colonial postmarks that document postal routes are all actively collected fields. The date recorded by a postmark can definitively authenticate a stamp — proving it was in use during a particular period — and postmarks have been used forensically to expose forged stamps falsely presented as pre-issue or period examples.