4/20/2023 0 Comments Visual watermark avis![]() ![]() issues, but some countries continue to use them. Watermarks were nearly universal on stamps in the 19th and early 20th centuries, but generally fell out of use and are not commonly used on modern U.S. The "classic" stamp watermark is a small crown or other national symbol, appearing either once on each stamp or a continuous pattern. Collectors who encounter two otherwise identical stamps with different watermarks consider each stamp to be a separate identifiable issue. In philately, the watermark is a key feature of a stamp, and often constitutes the difference between a common and a rare stamp. The resulting watermark is generally much clearer and more detailed than those made by the Dandy Roll process, and as such Cylinder Mould Watermark Paper is the preferred type of watermarked paper for banknotes, passports, motor vehicle titles, and other documents where it is an important anti-counterfeiting measure.Ī US postal stationery envelope from 1883 showing a clear watermark on laid paper. Once dry, the paper may then be rolled again to produce a watermark of even thickness but with varying density. Instead of using a wire covering for the dandy roll, the shaded watermark is created by areas of relief on the roll's own surface. It is a shaded watermark first used in 1848 that incorporates tonal depth and creates a greyscale image. Cylinder mould process Īnother type of watermark is called the cylinder mould watermark. This method is called line drawing watermarks. ![]() If the lines appear as a mesh or are indiscernible, and/or there is no watermark, then it is called wove paper. If these lines are distinct and parallel, and/or there is a watermark, then the paper is termed laid paper. Because the patterned portion of the page is thinner, it transmits more light through and therefore has a lighter appearance than the surrounding paper. This embossing is transferred to the pulp fibres, compressing and reducing their thickness in that area. Because the chain wires are located on the outside of the laid wires, they have a greater influence on the impression in the pulp, hence their bolder appearance than the laid wire lines. Faint lines are made by laid wires that run parallel to the axis of the dandy roll, and the bold lines are made by chain wires that run around the circumference to secure the laid wires to the roll from the outside. ![]() The dandy roll is a light roller covered by material similar to window screen that is embossed with a pattern. The invention of the dandy roll in 1826 by John Marshall revolutionised the watermark process and made it easier for producers to watermark their paper. Traditionally, a watermark was made by impressing a water-coated metal stamp onto the paper during manufacturing. Processes Dandy roll process Ī perspective view of a dandy roll in accordance with the invention of a conventional paper-making machine incorporating watermarks into the paper. Watermarks were first introduced in Fabriano, Italy, in 1282. This was done while the paper was still wet/watery and therefore the mark created by this process is called a watermark. At that time the watermark was created by changing the thickness of the paper and thereby creating a shadow/lightness in the watermarked paper. The origin of the water part of a watermark can be found back when a watermark was something that only existed in paper. In another instance, identifying codes can be encoded as a digital watermark for a music, video, picture, or other file. In one case, overprint on computer-printed output may be used to identify output from an unlicensed trial version of a program. The word is also used for digital practices that share similarities with physical watermarks. Various aids have been developed, such as watermark fluid that wets the paper without damaging it.Ī watermark is very useful in the examination of paper because it can be used for dating documents and artworks, identifying sizes, mill trademarks and locations, and determining the quality of a sheet of paper. Watermarks vary greatly in their visibility while some are obvious on casual inspection, others require some study to pick out. There are two main ways of producing watermarks in paper the dandy roll process, and the more complex cylinder mould process. Watermarks have been used on postage stamps, currency, and other government documents to discourage counterfeiting. A twenty euro banknote held against the light to show the watermark and the denomination.Ī watermark is an identifying image or pattern in paper that appears as various shades of lightness/darkness when viewed by transmitted light (or when viewed by reflected light, atop a dark background), caused by thickness or density variations in the paper. ![]()
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