Perforation varieties can make the difference

Apr 29, 2021, 7 PM
Figure 1. The 29¢ Hank Williams stamp was issued in 1993 with two different perforation measurements. The perforation gauge is a tool that measures stamp perforations. Click on image to enlarge.

By Michael Baadke

Although you may have two stamps that appear to be identical, the tiniest differences between them can make a big difference in identification.

It may be hard to believe, but even small differences in the type of perforations a stamp has can lead to big differences in catalog values.

The reason usually boils down to scarcity.

Sometimes only a few stamps are created with a specific perforation variety. When collectors learn of the variety and want to add it to their collections, demand may exceed the available supply and cause prices to climb quickly.

Fortunately, collectors have a fairly simple method to distinguish different perforation measurements and identify varieties.

In last week's Refresher Course I described how perforations are the small holes that surround each stamp on a pane. When a mailer or collector wants to remove one stamp from the pane, careful tearing through the perforation holes will do the trick.

Many stamp catalogs, such as those sold by Scott Publishing Co., include information about perforation measurement for every perforated stamp.

To measure perforations, collectors use a tool similar to a ruler called a perforation gauge.

Here is one confusing point: The word "gauge" is used to describe the actual measurement of the perforation as well as the tool used to do the measuring.

So, a collector may say "The gauge of the 29¢ Grace Kelly stamp is perf. 11."

And he uses a perforation gauge to make that determination.

The measurement of a stamp's perforations is described and listed as the number of perforation teeth or holes that are found within the space of two centimeters.

The description "perf. 11" means that the perforations on each side of the stamp measure in such a way that the stamp would have 11 perforation teeth or holes within the space of two centimeters.

Figure 1 shows how a collector uses a perforation gauge to make the proper measurement.

The clear plastic gauge shown in the illustration is called a Linn's Multi-Gauge.

The stamp being measured is the 29¢ Hank Williams stamp issued in 1993 in panes of 40.

Above the stamp illustration is an edited version of the listing for the Hank Williams stamp from the 1999 Scott Specialized Catalogue of United States Stamps.

Across the top is the notation "Perf. 10," indicating that this stamp should measure with a gauge of 10 on all four sides.

To measure the stamp, the collector places it upon the measuring scale in the center of the Multi-Gauge, and slides the stamp up or down until the slanted vertical lines precisely intersect with each perforation hole or tooth on the stamp.

In the stamp shown at left in Figure 1, the perforations along the top of the stamp are being measured.

Each perforation tip is lined up with the slanting vertical lines precisely where the tool reads "10" (at left).

That measurement helps to identify this stamp as Scott 2723.

Look again at the Scott catalog listing above the Figure 1 illustration. Near the bottom of the description is a listing for a perforation variety of the Hank Williams stamp.

The small letter "a" (indicating Scott 2723a) describes "Perf. 11.2 X 11.4."

This type of measurement with two figures is called a compound perforation.

The horizontal (top and bottom) perforations are different from the vertical (side) perforations. In such a measurement the horizontal perforations are always listed first (in this case, 11.2) and the vertical perforations are listed second (in this case, 11.4).

This unusual perforation variety for the Hank Williams stamp is harder to find than the standard perforate 10 issue. An example of this stamp is shown on the Multi-Gauge at right in Figure 1.

The perforation tips along the top of the stamp align with the vertical lines precisely where the tool reads "11.2."

Now here is a shortcut you can use when looking for scarce perforation varieties.

Once you've identified a common variety, such as the 29¢ Hank Williams stamp at left, you can use the actual stamp to check other examples of the same design.

Place the common stamp directly on top of the stamp in question. If the perforations match up perfectly, the stamp you're checking is also the common variety.

If the perforations don't quite match, check it again using the perforation gauge. You may have found the scarce variety.

Another fairly modern stamp with scarce perforation varieties is the 13¢ Eagle and Shield stamp of 1975 from the U.S. Americana series.

As shown at the bottom of Figure 2, the stamp has been found as an imperforate error. The Scott specialized catalog listing (Figure 2, top) lists "Imperf., pair," under the small letter "a."

Pairs are usually required to prove a stamp is an imperforate error. A single stamp with no perforations around it could simply be a normal stamp with the edges carefully trimmed off.

Near the top of the Scott listing is shown the perforation gauge, 11.2, for Scott 1596, the standard issue of this stamp.

A second minor listing (Scott 1596d) includes the notation "Line perforated."

A note at the end of the listing adds this description: "On No. 1596 the entire sheet is perforated at one time so the perforations meet perfectly at the corners of the stamp. On No. 1596d the perforations do not line up perfectly and are perf. 11."

The perforation gauge can be used to distinguish these two varieties, but the difference between perforate 11.2 for the normal issue and perforate 11 for the scarce variety are quite close and can be a little tricky to determine.

The difference is shown more clearly in the Figure 3 illustration of two 12-stamp plate blocks of the 13¢ Eagle and Shield issue.

At left is the normal issue, which measures gauge 11.2. A close look at the intersections of the horizontal and vertical perforations shows that they meet perfectly each time (one such intersection is shown in the enlargement at top left of Figure 3).

At right is the scarce issue, which measures gauge 11. The perforation intersections may meet close to perfect in some instances, but more often, they are a little off, as shown in the enlargement at top right of Figure 3.

The difference between these two issues can also be seen in the margin paper. The perforations end before reaching the edge of the pane for the normal variety and extend to the edge of the scarce variety.

A collector with both of these blocks will find the common plate block of 12 listing at $3.25 and the scarce block at $375.

Many worldwide stamps have similar perforation differences between otherwise identical stamps, making perforation measurement an important part of your enjoyment and understanding of the stamp hobby.

The Linn's Multi-Gauge is available from stamp dealers or from Linn's Stamp News for $6.95 plus $1 postage.

To order, visit look for Linn's Multi-Gauge under "Quick Navigation" and click on "Preview this item!"