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.
From Wikipedia About a year later inthese were replaced by stamps with an overprint in seriffed capitals, and these exist with two different watermarks.
This embossing is transferred to the pulp fibrescompressing and reducing their thickness in that area. From Wikipedia Since watermarks must be inserted into the video, they only identify copies of the particular video made after that point in time. 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.
Because the patterned portion of the page is thinner, it transmits more light through and therefore has a lighter appearance than the surrounding paper.
From There are no watermarks or limitations, regardless of creation method. From Wikipedia He has worked on problems to do with stereo and motion correspondence and multimedia issues of image database retrieval and watermarking.