How did perforations change the way postage stamps were separated from a sheet?

Before the introduction of perforations, postage stamps were printed on sheets without any built-in method for separation, requiring the use of scissors or a knife to cut individual stamps from the sheet.1

Between 1848 and 1854, the British Post Office adapted a machine to create separations during the manufacturing process. These separations, known as perforations, consist of tiny holes along the edges of the stamps that allow them to be easily and cleanly separated by hand.1

Various specialized methods for creating these separations were later developed, such as:

• Comb perforation: A machine that punches both the vertical and horizontal perforations for a row of stamps in a single stroke.2
• Compound perforation: A style where the stamps have different perforation measurements for the top/bottom edges compared to the side edges.3
• Interrupted perforation: A design featuring unperforated spaces between groups of holes, specifically used for stamps intended for vending machines or dispensers.4