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How to Use a Perforation Gauge


How to Use a Perforation Gauge


The size of the perforation between stamps is sometimes the only way a collector can differentiate between two ‘face identical’ stamps. This can make the proper use of a Perforation Gauge key to building a collection. Not only is it important for building a complete collection, but the difference in values between the otherwise identical stamps can be substantial.

A very simple example, that many collectors will encounter, can be found in the 1-cent green issue of the United States for the 1913 Panama-Pacific Exposition. Scott values the #397, with a perf of 12 at $1.50 but the same stamp perf. 10 values at $5.50 (Scott #401).

So what is perforation? Perforation is a process whereby the paper between the stamps is cut away by a line of holes leaving small attachment points, called teeth, that hold the sheet of stamps together but allow for easy removal of stamps from the sheet.

The users of stamps are concerned that their stamps stay together in sheets until used, when they can be separated easily. Over time various perforations have been used with varying results. For collectors this has created stamp varieties that makes stamp identification an interesting aspect of our hobby.

There are several types of perforation:

  1. Comb perforation - three sides of a stamp are perforated at once, with the process repeated in rows.
  2. Harrow perforation - the entire sheet or unit of stamps is perforated in one operation.
  3. Line perforation - holes are punched one row at a time.
  4. Syncopated perfs – some holes are omitted to create distinctive patterns, in order to help prevent counterfeiting. (Issues from the Netherlands from 1925-33, and issues of Great Britain beginning in 1992 are good examples of this perforation type).
  5. Hyphen-hole perfs - Often confused with roulettes, the perforations are in the form of elongated holes (paper has actually been removed, differentiating the perf from roulette)
  6. Microperfs – A new type of perforation found primarily on postal stationery, uses tiny perforations (as many as several hundreds of holes per two centimeters), which allow for easy separation, while preventing accidental separation.

Netherlands Syncopated

Breat Britain Syncopated

Line perforations are distinguished by the uneven crossing of perforation lines and irregular corners. Comb and harrow perforations usually show alignment of holes at the corners. It can be difficult to distinguish between the first three types of perforation on single stamps, while the irregular nature of the comb perforation is more easily seen in blocks of four or more stamps.

To measure perforations we are concerned with the number of holes (perforations, or perfs) in 2 centimeters. Thus, a perf. 11 size stamp has 11 holes in every 2 centimeters. Do not count the number of teeth, but rather the number of perforations, or holes.

Often, stamps will have a different perf size on the sides than they do on the top and bottom. Known as compound perfs, the first number will be the top measurement. The second number is the side perf size. As an example, most U.S. commemoratives are compound perfs of 10-1/2 x 11. In some rare instances the perf size can be different on more than two sides. In these instances the protocol calls for measuring the top first, then the right side, then the bottom, then the left side.

The degree of precision required depends on the level of specialization that the collector pursues. For most of us, measurement in half sizes is adequate. The simple Slotted Aluminum Perforation Gauge is an ideal tool for this level of precision. Simply set the stamp against the teeth of the stamp. When the dots on the gauge match the perforations on the stamp you have identified the correct size. Use the cutout slot for matching of mounted stamps and stamps on cover.

The specialist may wish to make a more precise determination of the perf size of a stamp. For this purpose a ‘specialist gauge’ such as the Linn’s Multi Gauge, offers precision in tenths of a centimeter. This precision is accomplished by use of a converging-lines grid. The stamp being sized is placed on the grid and slid along the surface of the gauge until the lines on the gauge perfectly project from the center of the teeth or perfs. The number to the side of the line indicates the size.

Ready? Here is an interesting exercise for the new collector.

The development of the modern day stamp in the United States is largely the result of experimentation by the Bureau of Printing and Engraving during production of the Washington-Franklin ‘Heads’, the regular issues between 1908 and 1929. The Bureau experimented with various perforations, in addition to watermarks, and three types of printing presses.

The result is about 250 different Scott Number stamps with just five different Scott Illustration Numbers, in six different sets. These stamps run in value from the most common and inexpensive to extremely rare and expensive, with plenty of stamps that will be of interest to all collectors.

Take a packet of these stamps and use your Perforation Gauge to identify the stamps by perf size. You will find that at the end of this exercise you will be adept at using the important Perforation Gauge tool.

Linn's Multi-Gauge
A large plastic gauge that measures watermarks, surcharges, perforations, grills, and overprints in millimeters, centimeters, and inches.

Linn's Multi-gauge
Slotted Aluminum Perforation Gauge
A sturdy perforation-gauge with cutout inside gauge to allow for easy matching of mounted stamps. In addition to perforation gauge, includes inches and millimeter measurements.

Metal perforation gauge