Which 15ยข stamp?
How to determine which perforation
Probably the most referenced measurement in stamps are the watermark and the perforation size. Perforation gauges as seen above cost just a few dollars and are an invaluable tool in philately. By placing the stamp, as shown above against the various illustrations of perforation gauges you can see which gauge matches the perforation on your stamp. In the example above the stamp is a perf 10 on the top and on the side. It is a good idea to measure both the vertical and horizontal sides as some stamps are perforated 11 x 10, 10 x 11, etc. The top perforation is always quoted first on this site and in stamp catalogues.
Watermarks
Between 1895 and 1916 the U.S. government used two different watermarks, double line and single line with the letters "USPS".
By placing the watermark face down on a dark surface or holding it up to bright light you might be able to see the watermark. If on the 1895 to 1916 stamp you cannot see the watermark it might be a good idea to invest in Watermark fluid and a watermark tray (examples are shown later). Ronsons lighter fluid works just as well as watermark fluid. Both fluids evaporate quickly.
Put enough fluid in the bottom of the tray, lay the stamp face down. In a few seconds the stamp will absorb the fluid and reveal the watermark to you.
As you will see from the illustrations the letters can span several stamps, so on the watermark, for instance, you can see only part of the letter S in one corner and only part the letter P in the other corner.
Watermarks
Between 1895 and 1916 the U.S. government used two different watermarks, double line and single line with the letters "USPS".
By placing the watermark face down on a dark surface or holding it up to bright light you might be able to see the watermark. If on the 1895 to 1916 stamp you cannot see the watermark it might be a good idea to invest in Watermark fluid and a watermark tray (examples are shown later). Ronsons lighter fluid works just as well as watermark fluid. Both fluids evaporate quickly.
Put enough fluid in the bottom of the tray, lay the stamp face down. In a few seconds the stamp will absorb the fluid and reveal the watermark to you.
As you will see from the illustrations the letters can span several stamps, so on the watermark, for instance, you can see only part of the letter S in one corner and only part the letter P in the other corner.
Bluish Paper
Watermarks
Between 1895 and 1916 the U.S. government used two different watermarks, double line and single line with the letters "USPS".
By placing the watermark face down on a dark surface or holding it up to bright light you might be able to see the watermark. If on the 1895 to 1916 stamp you cannot see the watermark it might be a good idea to invest in Watermark fluid and a watermark tray (examples are shown later). Ronsons lighter fluid works just as well as watermark fluid. Both fluids evaporate quickly.
Put enough fluid in the bottom of the tray, lay the stamp face down. In a few seconds the stamp will absorb the fluid and reveal the watermark to you.
As you will see from the illustrations the letters can span several stamps, so on the watermark, for instance, you can see only part of the letter S in one corner and only part the letter P in the other corner.
