Watermark

Watermark
a 50 euro banknote held against light to show the watermark

A watermark is a recognizable 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.[1] There are two main ways of producing watermarks in paper; the dandy roll process, and the more complex cylinder mould process.

Watermarks vary greatly in their visibility; while some are obvious on casual inspection, others require some study to pick out. Various aids have been developed, such as watermark fluid that wets the paper without damaging it. Watermarks are often used as security features of banknotes, passports, postage stamps, and other documents to prevent counterfeiting (see security paper).

A watermark is very useful in the examination of paper because it can be used for dating, identifying sizes, mill trademarks and locations, and the quality of a paper.

Encoding an identifying code into digitized music, video, picture, or other file is known as a digital watermark.

Contents

Dandy roll process

A watermark is made by impressing a water-coated metal stamp or dandy roll onto the paper during manufacturing. These watermarks were first introduced in Bologna, Italy, in 1282(?);[2] however the dandy roll was invented in 1826 by John Marshall. Watermarks have been used by papermakers to identify their product, and also on postage stamps, currency, and other government documents to discourage counterfeiting. In France, they were introduced during World War II by the Vichy regime, and counterfeited by people such as Adolfo Kaminsky. The invention of the dandy roll revolutionised the watermark process and made it much easier for a company to watermark its paper.

The dandy roll is a light roller covered by material similar to window screen that is embossed with a pattern. 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. 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.

This embossing is transferred to the pulp fibres, compressing and reducing their thickness in that area. Because the patterned portion of the page is thinner, it transmits more light through and therefore has a lighter appearance than the surrounding paper. If these lines are distinct and parallel, and/or there is a watermark, then the paper is termed laid paper. If the lines appear as a mesh or are indiscernible, and/or there is no watermark, then it is called wove paper. This method is called line drawing watermarks

Cylinder mould process

Another type of watermark is called the cylinder mould watermark. A shaded watermark, first used in 1848, incorporates tonal depth and creates a greyscale image. 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. Once dry, the paper may then be rolled again to produce a watermark of even thickness but with varying density. 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.

Watermarks on postage stamps and stationery

Elephant head watermark used on early stamps of India.
A US postal stationery envelope from 1883 showing a clear watermark on laid paper.

In philately, the watermark is a key feature of a stamp, and often constitutes the difference between a common and a rare stamp. Collectors who encounter two otherwise identical stamps with different watermarks consider each stamp to be a separate identifiable issue.[3] The "classic" stamp watermark is a small crown or other national symbol, appearing either once on each stamp or a continuous pattern. 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. issues, but some countries continue to use them.[4]

Some types of embossing, such as that used to make the "cross on oval" design on early stamps of Switzerland, resemble a watermark in that the paper is thinner, but can be distinguished by having sharper edges than is usual for a normal watermark. Stamp paper watermarks also show various designs, letters, numbers and pictorial elements.

The process of bringing out the stamp watermark is fairly simple. Sometimes a watermark in stamp paper can be seen just by looking at the unprinted back side of a stamp. More often, the collector must use a few basic items to get a good look at the watermark. For example, watermark fluid may be applied to the back of a stamp to temporarily reveal the watermark.[4]

Even using the simple watermarking method described, it can be difficult to distinguish some watermarks. Watermarks on stamps printed in yellow and orange can be particularly difficult to see. A few mechanical devices are also are used by collectors to detect watermarks on stamps such as the Morley-Bright watermark detector and the more expensive Safe Signoscope. Such devices can be very useful for they can be used without the application of watermark fluid and also allow the collector to look at the watermark for a longer period of time to more easily detect the watermark.

See also

References

  1. ^ Biermann, Christopher J. (1996). "7". Handbook of Pulping and Papermaking (2 ed.). San Diego, California, USA: Academic Press. p. 171. ISBN 0-12-097362-6. 
  2. ^ Meggs, Philip B. (1998). A History of Graphic Design (Third ed.). John Wiley & Sons, Inc.. pp. 58. ISBN 978-0471291985. 
  3. ^ "Miller, Rick; Stamp identification often lurks in watermark in Linns.com Refresher Course section". http://www.linns.com/howto/refresher/watermark_20051010/refreshercourse.aspx. 
  4. ^ a b "Baadke, Michael; How to identify a stamp by its watermark in Linns.com Refresher Course section". http://www.linns.com/howto/refresher/watermarks_19981005/refreshercourse.aspx. 

External links

Watermarks in databases and other watermark projects:

Bibliography on watermarks and papers in Greek manuscripts:


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • watermark — wa‧ter‧mark [ˈwɔːtəmɑːk ǁ ˈwɒːtərmɑːrk, ˈwɑː ] noun [countable] 1. a design that is put into paper that you can see when you hold it up to the light: • Banknotes have a watermark to prevent forgery. 2. COMPUTING an electronic device in text,… …   Financial and business terms

  • Watermark — LP de Enya Publicación septiembre de 1988 Grabación 1987 Género(s) New Age Duración …   Wikipedia Español

  • Watermark — (Oneroa,Новая Зеландия) Категория отеля: 4 звездочный отель Адрес: 17 Tawa Street, 1081 Oneroa, Нова …   Каталог отелей

  • Watermark — Wa ter*mark , n. 1. A mark indicating the height to which water has risen, or at which it has stood; the usual limit of high or low water. [1913 Webster] 2. A letter, device, or the like, wrought into paper during the process of manufacture.… …   The Collaborative International Dictionary of English

  • watermark — [wôt′ərmärk΄] n. 1. a mark showing the limit to which water has risen 2. Papermaking a) a translucent mark in paper, produced by the pressing of a projecting design, as in the mold, during manufacture b) the design vt. 1. to mark (paper) with a… …   English World dictionary

  • watermark — index brand Burton s Legal Thesaurus. William C. Burton. 2006 watermark n …   Law dictionary

  • watermark — (n.) 1708, distinctive mark on paper, from WATER (Cf. water) (n.1) + MARK (Cf. mark) (n.1). Cf. Ger. wassermarke. Not produced by water, but probably so called because it looks like a wet spot. The verb is recorded from 1866 …   Etymology dictionary

  • watermark — ► NOUN ▪ a faint design made in some paper during manufacture that is visible when held against the light, identifying the maker. ► VERB ▪ mark with such a design …   English terms dictionary

  • watermark — wa|ter|mark [ˈwo:təma:k US ˈwo:tərma:rk, ˈwa: ] n 1.) a special design put onto paper, especially bank notes, that can only be seen when you hold it up to the light bear/carry a watermark ▪ The sheet bears the watermark 1836 . 2.) a special mark… …   Dictionary of contemporary English

  • Watermark — Эта статья о музыкальном альбоме, о водяных знаках см. другую статью Watermark …   Википедия

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”