Perforation Varieties
Also called perfs, perforation measuring.
Period: 1854 onward
The single most important technical measurement in the hobby, and the one that most often separates a common stamp from a rare one. Two stamps identical in every visible respect can differ enormously in value on a perforation count.
What you are looking at
The holes punched between stamps so they can be separated. Counted per two centimetres.
What to check
- Measure with a perforation gauge — a printed card with graduated rows of dots. Lay the stamp on it until the dots align exactly.
- The result is expressed as holes per 2 cm, typically between 10 and 15.
- Compound perforations differ on the horizontal and vertical edges and are written as two numbers, for example 'perf 12 x 11½'.
- Imperforate means no holes at all — genuine imperforates are usually issued that way, and cut-down perforated stamps are a common fake.
- Rouletted stamps have cuts or pierces rather than removed paper, with no holes.
What it is worth
This is where value hides. A perforation variety can be worth hundreds of times a common one from the same issue, which is why the gauge is the first tool anyone serious buys.
Confused with
A perforated stamp with the perfs cut off to imitate an imperforate. The margins will be uneven and the paper edge will show tiny remnants under magnification.
Questions about this
How do you identify perforation varieties?
Measure with a perforation gauge — a printed card with graduated rows of dots. Lay the stamp on it until the dots align exactly. The result is expressed as holes per 2 cm, typically between 10 and 15.
Are perforation varieties valuable?
This is where value hides. A perforation variety can be worth hundreds of times a common one from the same issue, which is why the gauge is the first tool anyone serious buys.