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Information about Watermark

This article is about physical paper watermarks. For other uses, see Watermark (disambiguation).
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This "Crown & CA" (for "Crown Agent") watermark was standard for postage stamps of the British colonies from the 1880s to the 1920s.


A watermark is a recognizable image or pattern in paper that appears lighter when viewed by transmitted light (or darker when viewed by reflected light, atop a dark background). A watermark is made by impressing a water-coated metal stamp or dandy roll onto the paper during manufacturing. Watermarks were first introduced in Bologna, Italy in 1282; they have been used by papermakers to identify their product, and also on postage stamps, currency, and other government documents to discourage counterfeiting.

Technique

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.

Another type of watermark is called the shaded 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. 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.

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.

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

Watermarks on postage stamps

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Elephant head watermark used on early stamps of India.


In philately, the watermark is a key feature of the stamp, and often constitutes the difference between a common and a rare stamp. 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 issues.

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.

See also

External links

Watermarks in databases and other Watermark projects:
Watermark can refer to:
  • Watermark, a recognizable image or pattern in paper used to identify authenticity
  • Watermark (album), a 1988 album by Enya
  • Watermark (band), a CCM singing duo comprising Nathan and Christy Nockels

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Paper is thin material used for writing upon, printing upon or packaging, produced by the amalgamation of fibres, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding.
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Paper is thin material used for writing upon, printing upon or packaging, produced by the amalgamation of fibres, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding.
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Country Italy
Region Emilia-Romagna
Province Bologna (BO)
Mayor Sergio Cofferati

Area km
Population
 - Total
 - Density /km
Time zone CET, UTC+1
Coordinates
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Anthem
Il Canto degli Italiani
(also known as Fratelli d'Italia)


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1282 in other calendars
Gregorian calendar 1282
MCCLXXXII
Ab urbe condita 2035
Armenian calendar 731
ԹՎ ՉԼԱ
Bah' calendar -562 – -561
Buddhist calendar 1826
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A postage stamp is evidence of pre-paying a fee for postal services. Usually a small paper rectangle or square that is attached to an envelope, the postage stamp signifies that the person sending the letter or package may have either fully, or perhaps partly, pre-paid for delivery.
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currency is a unit of exchange, facilitating the transfer of goods and/or services. It is one form of money, where money is anything that serves as a medium of exchange, a store of value, and a standard of value. A currency is the dominant medium of exchange.
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worldwide view of the subject.
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A counterfeit is an imitation that is made usually with the intent to deceptively represent its content or origins.
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Screen may mean:
  • Window screen, a wire mesh that covers a window opening
  • Fire screen
  • Windshield (windscreen), protects the driver of a vehicle
  • Screen-printing (silk-screening), a method of printing
  • Projection screen, a viewing surface

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Wood pulp is a dry fiberous material prepared by chemically or mechanically separating the fibers which make up wood. Pulp can be either fluffy or formed into thick sheets. The latter form is used if the pulp must be transported from the pulp mill to a paper mill.
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For other meanings of fiber/fibre please see Fiber (disambiguation).


Fiber or fibre[1] is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.
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page is one side of a leaf of paper. It can be used as a measurement of documenting or recording quantity ("that topic covers twelve pages").

The page in typography


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Light is electromagnetic radiation of a wavelength that is visible to the eye (visible light). In a scientific context, the word "light" is sometimes used to refer to the entire electromagnetic spectrum.
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18th century - 19th century - 20th century
1810s  1820s  1830s  - 1840s -  1850s  1860s  1870s
1845 1846 1847 - 1848 - 1849 1850 1851

:
Subjects:     Archaeology - Architecture -
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IMAGE (from Imager for Magnetopause-to-Aurora Global Exploration), or Explorer 78, was a NASA MIDEX mission that studied the global response of the Earth's magnetosphere to changes in the solar wind.
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Questioned document examination (QDE) is known by many names including forensic document examination, document examination, diplomatics, handwriting examination, and sometimes handwriting analysis
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Video (Latin for "I see", first person singular present, indicative of videre, "to see") is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.
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IMAGE (from Imager for Magnetopause-to-Aurora Global Exploration), or Explorer 78, was a NASA MIDEX mission that studied the global response of the Earth's magnetosphere to changes in the solar wind.
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Digital watermarking is a technique which allows an individual to add hidden copyright notices or other verification messages to digital audio, video, or image signals and documents.
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Philately is the study of revenue and postage stamps. This includes the design, production and uses of stamps after they are authorized for issue, usually by government authorities, the most common one being postal authorities.
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Embossing is the process of creating a three-dimensional image or design in paper and other ductile materials. It is typically accomplished with a combination of heat and pressure on the paper.
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Motto
Unus pro omnibus, omnes pro uno (Latin) (traditional)[1]
"One for all, all for one"
Anthem
"Swiss Psalm"
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Thomas Harry Saunders (19 September1813, London - 5 February1870, Dartford), usually called T. H. Saunders, was a British paper-maker known especially for his watermarks, and also a philanthropist.
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Dirty paper coding (DPC) is a coding technique that pre-cancels a known interference where the known interference is interference known at the transmitter before self-data transmission.
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