FAQ-What are stamp perforations?

One of the aspects of correctly identifying your stamps which requires a bit of skill is measuring perforations. Before we get to that however, it’s a good idea to understand what stamp perforations are.

Punched out perf holes on a stamp sheet
Punched out perf holes on a stamp sheet

What are stamp perforations (or «perfs»)?

Perforations are the little holes punched in a row across sheets of stamps that enable us to easily separate one stamp from another. If the punched out holes were not there, we would have to cut out each stamp by hand with a pair of scissors. Once stamps are separated from one another, the torn perforation holes appear as a wavy line along the sides of the stamp.


Typical perforation gauge
Typical perforation gauge

What is a «perf measure»?

The more punched out holes there are in a row, the easier it will be to tear one stamp from another. But if there are too many holes, then a stamp sheet will start falling apart because there is not enough paper in between the holes to keep it together. Various postal agencies from different countries have long experimented with the right ratio of perforations to paper.

A perf measure is said to be the number of perforation holes contained within a length or width of 2 cm.The perf measure of a stamp can be the same on both the horizontal and vertical sides. Or, the horizontal sides of the stamp can be one measure and the vertical sides a different measure. When the measurements are not the same, the first number is the measurement for the horizontal sides and the second number is for the vertical sides of the stamp. The perf measure of a stamp can be measured with a perforation gauge.


Well centered imperforate stamp
Well centered imperforate stamp

What is an imperforate stamp?

An imperforate stamp is a stamp that had no perforation holes punched along its sides at the time of its printing. These stamps had to be cut one from another by hand, generally with a pair of scissors. Therefore imperforate stamps have straight edges. However, since they were cut by hand, these edges are often uneven, making the stamp off-centered. Many early stamps were imperforate. An imperforate stamp that was neatly and evenly cut on all four sides will be highly prized by collectors.



 Does the perf measure of a stamp affect its value?

Yes, the perf measure can sometimes greatly affect the value of a stamp. Two stamps may seem identical and yet be different due to their perf measures being different. If one perf measure is more rare than another, this can make that particular stamp more highly prized to collectors, thereby increasing its value.

For example: Unitrade #1175 with perf 14.4 x 13.8 is valued at $1.50, whereas the same stamp with perf 13.1 on all sides is valued at $100!

Also: Unitrade #35 with perf 12 on all sides is valued at $60, whereas the same stamp with perf 11½ x 12 is valued at $600!

This is why it is a good idea to check the perf measure one some of your stamps. You never know when you may have a rarity hiding among seemingly common stamps! Of course, this is also why it is practical to own a Unitrade catalogue, which lists the perf measure of all Canada stamps, as well as a perforation gauge.

Our next article will explain how to read and measure stamp perforations with your perforation gauge.

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