Perforations

Before perforations: scissors

From 1840 until about 1850 every stamp was issued imperforate. Clerks and customers cut stamps apart with scissors or tore them along a metal ruler, which is why so many early stamps have uneven margins or are cut into the design.

Henry Archer patented a perforating machine in Britain in 1848. His own machine proved the idea but never entered regular service; he perforated some Penny Red plates experimentally in 1850, and machines built on his principles perforated British stamps from early 1854, first at 16 holes per 2 cm and from January 1855 at 14. In the United States, the earliest known use of a perforated stamp is February 28, 1857, and the 1857–61 issues gauge 15½.

How a perforation gauge works

The gauge is the number of holes in a 2-centimeter span. "Perf 11" means 11 holes per 2 cm. Jacques Legrand invented the perforation gauge in 1866, and it is still the tool collectors use: a card or plastic scale printed with rows of dots at known spacings, which you slide along the stamp's edge until the dots line up with the holes.

Many stamps are perforated differently on the horizontal and vertical sides, a compound perforation written as 11 x 10½. By convention the horizontal measurement (top and bottom) comes first. Many US stamps are perforated 10½ x 11 or 11 x 10½.

Our free perforation gauge works on screen or printed at actual size.

Rouletting and imperforate stamps

• Rouletting uses small cuts in the paper instead of punched holes. No paper is removed, so a rouletted edge looks slit rather than holed.
• Imperforate stamps have no separation at all and must be cut from the sheet.
• Straight edges on one or two sides usually mean a booklet or coil stamp, or a sheet-margin copy, not an imperforate.

Perforation varieties attract fakes in both directions. Forgers add perforations to common imperforate stamps to imitate scarcer perforated ones (Mystic warns about exactly this for the 2¢ Scott 519), and trim perforations off sheet stamps to fake rare coils. Anything that depends on the perfs for its value should be certified.

Why perforations change value: the Washington-Franklins

The US Washington-Franklin series of 1908–1922 shows how much the gauge matters. It used only five basic designs but produced more than 250 distinct issues, largely through changes in perforation, watermark and printing method. Sheet stamps started at perf 12; coils were perforated 8½ from 1910 and 10 from 1914; later stamps came perf 10, 11, and compound 11 x 10.

The extreme case is the 3¢ "Orangeburg" coil of 1911, Scott 389, perforated 12 instead of the usual 8½ for coils of its time. Siegel Auction Galleries' census records 11 unused examples; a pair sold for $370,000 in April 2021. Wikipedia's summary is blunt: the spacing of the perforations "can influence the scarcity and therefore value of a stamp."