I frequently get questions about Washington-Franklin head coil stamps. Many of these coils are scarce or rare. /Fakes abound, especially on the rarest of coils. How do you know if the coil stamp is genuine or not?
Your best line of defense is a certificate of authenticity from one of the recognized expertizing agencies. Remember that these are an opinion of several experts who review the item (often referred to as ďthe patientĒ). Itís extremely rare, but certificates have been reversed. If you obtain a certificate of authenticity, you can be very certain that the item is genuine.
Certificates of authenticity cost money. Is there something you can do yourself to detect genuine coil stamps? Yes.
In 1965, Richard Kiusalas created a metal perforation gauge called the ďUnited States Specialist GaugeĒ. Itís 50 years old, but it is as useful today as it was when it was created. Obviously, no longer produced, you can find them at some dealers or online auctions. These gauges are not rare.
The gauge is for 12 different perforation sizes that were used. It goes from size 8.5 to size 12 perforation holes. For example, there are three sets of measurements for perf 10 stamps: 10-81, 10-80, and 10-79. The second number is the number of thousandths of an inch between each perforation hole. Thatís correct Ė every perf 10 stamp is not exactly the same. A perf 10 on one issue can vary slightly from a perf 10 on another issue. The differences are minute, but very important.
Kiusalas was able to create an aluminum gauge that precisely measures the different perforation sizes used on US stamps.
Here is the key point. If you have a coil stamp and youíre not sure if the perforations are genuine or not, use the Kiusalas gauge. A genuine stamp will match the hole pattern EXACTLY. There should be no variance at all. If the holes donít match up precisely to one of the sizes on the gauge, itís almost certainly a fake stamp.
If you canít find an original Kiusalas gauge, you can find the US Specialty Precision Multi-Gauge which is available from Sonic Imagery Labs. This gauge is very useful and does more than just measure perforations. However, the perforation scale used on this gauge is based on the original Kiusalas gauge. They cost about $15.
Although the Kiusalas gauge is useful for coil stamps, it is useful for all US stamps. You can use it to detect genuine perforations on sheet stamps as well.
One last tip. Perforations are created on stamps by wheels of metal pins that punch the perforations. As the sheets of stamps are fed into the perforating machine, the perforations are created. Since the wheels are moving in a circular motion, the perforation holes themselves usually exhibit two characteristics. First, the holes will exhibit a slightly oblong shape. Second, genuine perforations usually have some traces of paper fragments within the holes. To the naked eye, the hole may appear round and clean. Under 30x magnification (or higher), youíll notice that the holes are slightly oblong and there are minute paper fibers left behind.
If you examine a stamp under magnification and the holes are perfectly round and very smooth, itís almost certainly not a genuine perforation.
Good luck examining your perforations!