A watermark is an image, inscription or motif formed within the paper during manufacture. Variations in fibre distribution and paper thickness make the design appear lighter or darker when the paper is viewed in transmitted light.
Papermakers in Italy were already using such marks by the end of the 13th century. Watermarks remain an important feature of security paper because producing a genuine watermark requires specialised papermaking equipment.
Most Hungarian postage stamps issued between 1881 and 1962 were printed on watermarked paper. Exceptions included, among others, the 1925 Jókai and Sport issues and several engraved stamps produced between 1949 and 1952. After 1962, watermarks were no longer used for Hungarian postage stamps.
How is a watermark made?
A watermark is created during papermaking. Letters, numerals, symbols or designs made from wire are attached to the mesh covering a watermarking cylinder known as a dandy roll. These elements project slightly from the surface and press into the still-wet layer of paper fibres as the roll turns. The fibres are displaced, altering the density and thickness of the paper in those areas. When the finished paper is held to the light, the thinner areas transmit more light and the watermark becomes visible.
Why examine the watermark of a stamp?
Watermark examination is important primarily for the accurate identification of a stamp. Several Hungarian issues exist with the same printed design on papers bearing different watermarks, including many Krajcár and Turul issues. Catalogues list these separately, and the difference in value can be substantial.
For some issues, catalogues also distinguish different watermark positions. A scarcer watermark fragment, position or numeral watermark may significantly increase a stamp’s value. On crown watermarks, for example, different positions of the cross may also command very different catalogue values.
Irregularities may also occur during the manufacture of the watermark itself, such as incomplete or distorted motifs or traces of repairs to the watermarking mesh. Such features can also be of philatelic interest.
How should a watermark be examined?
The simplest method is to hold the stamp with tongs and view it against a light source. In many cases this is sufficient to identify the type and position of the watermark.
Watermarks that are difficult to see can traditionally be examined with watermark fluid and a black tray. The stamp is placed face down and moistened with a small amount of suitable fluid. Lighter fluid or petroleum ether was commonly used in the past, but such liquids are highly flammable and evaporate rapidly. They should only be used with good ventilation and well away from flames, sparks and heat sources; caution is also required with inks that may be sensitive to solvents.
Modern electronic and optical watermark detectors are also available and can help reveal watermark details without the use of liquid.
Important: the positions of Hungarian stamp watermarks are always classified as viewed from the printed side of the stamp.
Forged watermarks
Imitation watermarks are rare on stamps, but examples are known. A complete forgery of the 1924 Icarus issue exists, and some examples even entered postal circulation. The forgery was lithographed, and the supposed watermark was simply drawn on the reverse.
