Stamp Watermarks


Watermarks are images or patterns in stamp paper that look like various shades of lightness and darkness when seen. They are caused by variations in the thickness of the paper. Watermarks vary greatly in their visibility: some are very easily seen just by turning the stamp over or by holding it up to a light, while others are much more difficult to detect.

Because they can be hard to see, various tools to detect watermarks have been developed. Watermark fluid, which wets the stamp paper without damaging it or the stamp's gum, is the most commonly used tool. A variety of small light filters and other types of small tools are also used.

A watermark can be a key feature in identifying a stamp. Often the presence or absence of a watermark, or a specific watermark design, makes the difference between a rare, valuable stamp and a common stamp. Although stamps are generally not printed on watermarked paper now, watermarked stamp paper was in common use by much of the world during the 19th and early 20th centuries.
As a result, a stamp collector's ability to detect and identify stamp watermarks can make all the difference in the quality and value of his or her stamp collection.