A watermark is an invisible mark on a sheet of paper for identification purposes. It is a pattern made on papers by means of a raised or indented design that comes in contact with the paper when it is approximately 90% water and 10% fibers. The watermark becomes visible when the paper is immersed in water.
It can also be defined as 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 variations in the paper. Fabriano is the first company to use watermarks, towards the end of the 13th century.
Uses of Water mark
Watermarks are used for identification purposes. They are equivalent to the sewn-in label in a piece of clothing
They can also be used to write secret messages on sheets of paper.
Watermarks are often used as security features of banknotes, passports, postage stamps, and other documents to prevent counterfeiting.
A watermark is very useful in the examination of paper because it can be used for dating, identifying sizes, trademarks, locations, paper quality.
Pick a sheet of conqueror paper and hold it against the light, you will see the conqueror watermark on it.
Types of Watermark
There are three main ways of producing watermarks; - the dandy roll process, - the cylinder mould process and - the digital process.
A Dandy roll 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. However the dandy roll was invented in 1826 by John Marshall. The invention of the dandy roll revolutionised the watermark process and made it much easier for a company to watermark their paper.
For the Cylinder Mould method, the shaded watermark is created by areas of relief on the roll's own surface. 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.
The Digital water marks are made by computer programs and graphics. Digital watermarking is the process of embedding information into a digital signal in a way that is difficult to remove. The signal may be audio, pictures or video. If the signal is copied, then the information is also carried in the copy. A signal may carry several different watermarks at the same time.
How Watermarks Are Made
Watermarks are made by applying pressure that alters the fibers in the sheet of paper. This changes the reflection of light when the sheet is wet and hence the watermark becomes visible.
A watermark can be added either by it being part of the screen used for making the paper (it shows up because less paper pulp is used in this area), or by it being embossed (indented or pressurized) onto the paper when it is still wet.
Materials Needed (for class or homemade watermark)
A. Sheets of paper B. A sharpened pencil C. A sheet of Glass D. Water E. Table or a Flat surface
Creating a water mark on paper
Procedure 1. Dip your sheet of blank/plane paper in water. This should last for about 10 seconds. 2. Bring out the sheet of paper from the water and put it on a plane sheet of glass 3. Get a dry sheet of plain paper and place it over the wet sheet of paper. 4. Next write on the dry sheet of paper using a pencil. 5. Gently remove the dry sheet of paper from the wet one. 6. After removing the dry sheet of paper you will notice that the writing will be clearly seen on the wet sheet. 7. When the paper dries the writing will disappear, but will again reappear when the sheet is placed in water or when held up against light.
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