Stamp glossary
Watermarks
What a watermark is
The United States Stamp Society defines a watermark as "a pattern embedded in paper during the production process, created by an intentional thinning of the paper." Because the paper is thinner there, the design shows up when the stamp is backlit or wetted with fluid, not under normal light.
Watermarked paper made stamps harder to counterfeit. Wikipedia notes that watermarks were nearly universal on stamps in the 19th and early 20th centuries, and that a watermark "often constitutes the difference between a common and a rare stamp."
US stamp watermarks
| Watermark | Period | Notes |
|---|---|---|
| Double-line "USPS" | 1895 to 1910 | Introduced to deter counterfeiting |
| Single-line "USPS" | 1910 to 1916–17 | Replaced the double-line paper in 1910 |
| None | From the 1916–17 series | The 1916–17 series ended regular use of watermarked paper |
Within the 1908–1922 Washington-Franklin series, the watermark is one of the features that separates otherwise identical stamps. A 2¢ carmine Washington perforated 11 on double-line watermarked paper is Scott 519, which Mystic Stamp Company lists at $795; without the watermark and the perforations to match, it is a different catalog number.
Watermarks elsewhere
British stamps used crown watermarks from the start: a small crown on the early Penny Reds, replaced by a large crown from 15 May 1855. The "Crown CA" watermark appears on many British Commonwealth stamps, and catalogs list each watermark as a separate variety.
How to find a watermark
- Use a black watermark tray. Place the stamp face down in the tray.
- Add watermark fluid made for stamps until the stamp is covered. The watermark appears as a darker pattern within a second or two and fades as the fluid evaporates.
- Never use water. Mystic is firm on this, and warns to use only fluids made specifically for stamps, or you risk damaging them. It recommends a non-flammable, non-toxic product.
- Try a detector for fluid-free checks. Devices such as the Morley-Bright detector show watermarks without wetting the stamp.
- Expect trouble with yellow and orange stamps, where watermarks are especially hard to see.
A photo of the front of a stamp can't show its watermark, so photo identification, including StampSnap, gives you the issue and design but not the paper. Use our watermark finder to match what you see in the tray to a named watermark.
Watermarks: common questions
How do I see the watermark on a stamp?
Put the stamp face down in a black watermark tray and cover it with watermark fluid made for stamps. The pattern shows briefly as a darker area. Never use water.
Do all stamps have watermarks?
No. Watermarks were nearly universal in the 19th and early 20th centuries, but US stamps stopped using watermarked paper with the 1916–17 series, and many modern stamps have none.
What does the USPS watermark look like?
US stamps from 1895 to 1916–17 carry the letters USPS in either double-line (1895–1910) or single-line (from 1910) letters, repeated across the sheet, so a single stamp often shows only part of a letter.
Can I use lighter fluid to find watermarks?
Collectors have long used it, but Mystic recommends fluids made specifically for stamps, preferably non-flammable and non-toxic, because other substances can damage stamps.
Sources & References
- A Glossary of Terms for the Collector of United States Stamps - United States Stamp Society
- Watermarks - Mystic Stamp Company
- How to Identify Your Stamps - Mystic Stamp Company
- Watermark - Wikipedia
- Washington–Franklin Issues - Wikipedia
- Penny Red - Wikipedia
- 1908-15 Washington-Franklin Series - Robert A. Siegel Auction Galleries
- 519 - 1917 2c Washington, Double Line Watermark, Perf. 11 - Mystic Stamp Company
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