Part of the joy of collecting stamps is examining them – to discover their origin and history, or simply to enjoy them as works of art. But a close examination has a practical side as well. It can help detect a forgery or form part of the assessment of the stamp’s value. Part of that process involves looking for and identifying watermarks.
Watermarks have been part of stamp design since the beginning when the first British One Penny Black was produced in 1840, though the practice of watermarking itself is much older. According to some historians, watermark embedding in paper dates back as far as late-13th century Italy.
A watermark is a design impressed into the stamp during paper processing. They can enhance the esthetic appeal, but their primary purpose historically was to make it harder to counterfeit stamps. A similar process was used in paper currency for decades, though anti-forgery methods have become considerably more sophisticated.
The practice has uses other than counterfeit combating. Watermarks can aid in identifying the manufacturer of the paper used, verify the designer or date or simply add an interesting artistic element to the stamp.
All of these elements – the authenticity, the date, the design, etc – figure into the value of the stamp. Among other things, as with coins, the manufacturing process can go awry and produce slight flaws in the watermark. These can turn an ordinary stamp into a rarity, which usually increases its value.
Though watermarks have gone out of favor in recent decades older stamps almost always have them and there are several fairly standard types.
Unit watermarks are ones that are impressed on each individual stamp, typically by a component called a ‘dandy roll’. The dandy roll is a wire cylinder in a paper making machine that produces a texture or pattern in the paper.
Multiple watermarks are a more complex design and parts of it may end up on several different stamps. As a result, part of the adventure of philately can be to find enough stamps from a particular issue to complete the watermark.
Sheet watermarks are a design which covers an entire sheet of stamps. Hungary produced some stamps from 1898-1899 using this method. Finding enough stamps from one issue to complete the watermark design in this case would be a real challenge!
Watermarks can be detected by several different methods, some more effective than others depending on the circumstances.
Some watermarks can be made out simply by examining the stamp under a bright light. This is made easier if the stamp is unmounted, not attached to a cover, and can be viewed with the light shining through the stamp.
Other watermarks are more subtle and here technology has come to the aid of the philatelist. Watermark fluid is available that safely soaks the stamps, then dries quickly without leaving a residue. Fluorescent lamps are sometimes used in conjunction with the fluid or alone to detect watermarks. There are even special-made machines (the famed Morley-Bright, for example) that use no chemicals to aid in detecting the watermark.
Whichever method suits your budget or style, add watermark detection to your toolkit to learn as much as possible about your stamps.