A watermark is a translucent design impressed on paper during manufacture and visible when the paper is held to the light. The word watermark is composed of two Latin words: filum – thread and granum – grains, which emphasize the finesse of the watermark ornament. At first the information and documents on watermarks and the history of paper was accumulated by paleography. The filigranology as an auxiliary science of the history science emerged in the late nineteenth – early twentieth centuries. It studied the paper watermarks in order to determine their origin, the date of manufacture, quality and paper format. Filigranology helps paleography, bibliology and philology to locate, date and authenticate ancient documents. Filigranology also deals with the history of paper and the factories that produced it. That is why, the synonym of the word filigree is papermark or watermark.