For postage stamps, separation is the means by which individual stamps are made easily detachable from each other.
The Penny Black is imperforate.
Separation of imperforate stamps by scissors, knife or tearing often leads to uneven margins on the stamp as in this 1853 stamp of Van Diemen's Land.
Vertical pair of 1d red, from Plate 70, perforated with the Archer experimental roulette
Perforated and imperforate versions of the same Austrian stamp of 1920
A postage stamp is a small piece of paper issued by a post office, postal administration, or other authorized vendors to customers who pay postage. Then the stamp is affixed to the face or address-side of any item of mail—an envelope or other postal cover —which they wish to send. The item is then processed by the postal system, where a postmark or cancellation mark—in modern usage indicating date and point of origin of mailing—is applied to the stamp and its left and right sides to prevent its reuse. Next the item is delivered to its addressee.
The main components of a stamp: 1. Image 2. Perforations 3. Denomination 4. Country name
Lovrenc Košir, 1870s
Rowland Hill
The Penny Black, the world's first postage stamp (1 May 1840)
