Postmark
A postmark is a cancellation or marking made on a postage stamp, letter or package indicating its approximate date of use. (The postmark must be distinguished from the earliest cancellations, which simply cross out the stamps with a pen.) Postmarks can be either applied by hand or machine.
A postmark should not be confused with the killer which are lines, bars, etc. used to cancel a postage stamp. Neither should a postmark be confused with pre-cancels (stamps that have been cancelled before the envelope or package to which they are affixed is submitted or deposited for acceptance into the mailstream, they most commonly have taken the form of a pre-printed city name on the stamp), which generally do not indicate a date.
Datestamp is another word for postmark.
Postmarks were introduced to help track the delivery quality/speed of the postal service. In the 1800s and early 1900s it was common for letters to receive multiple postmarks indicating the time, date and location of each post office delivering/transporting the letter.
Stamp collectors like to see stamps which are either 'lightly cancelled' or which have 'bulls-eye cancellations'.
A lightly cancelled stamp would have the postmark on a corner or small portion of the stamp.
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. A special or rare postmark can substantially add to the value of a stamp. (In addition to everyday postmarks there are postmarks indicating the first day of issue of a particular stamp and pictorial cancellations commemorating local events, anniversaries and the like.)
Much of the published work on postmarks covers postmarks from before 1900. (This is perhaps because in the United States so-called fancy cancels were prevalent in this period, with the cancelling device often hand-cut by the postmaster in elaborate shapes such as flags, stars or shapes that were seasonally-appropriate such as turkeys for Thanksgiving). Much work in studying postmarks is needed for 1900 and later.
Fewer postmarks are used now than previously, with the advent of meter labels, which indicate the precise date and time of acceptance at the post office, and computerized postage people can print off their own PCs (in the United States these services were offered by such companies as Stamps.com and Neopost, Inc.).
External link:
- Precancels