vízjelek

vízjelek is the Hungarian term for watermarks, the faint designs that are embedded in paper or other substrates to provide identification or authentication. They originated in medieval Europe, where paper was produced by impressing a piece of paper or a watermark stencil onto wet paper pulp. The metaphorical "watermark" was named because the design appeared as a light or translucent pattern when held up to light, resembling a watermark on a document.

Modern watermarks are created through one of several techniques. Presswatermarks involve using a raised or depressed die pressed into wet pulp as it dries. Embossments are produced by clamping a pattern between two dies during press operation. For photographic film, silver halide emulsions can be coated with a gelatin layer containing a watermark that shows up when the film is processed. Digital watermarks, although not the same physical phenomenon, replicate the concept electronically by embedding hidden patterns or codes in images or documents for copyright protection.

Applications of vízjelek include safeguarding banknotes, passports, legal documents, and journalistic archives. They also serve as a deterrent against forgery, as the imprint requires specialized equipment. Detection of watermarks can be done by observing paper under ultraviolet light or through optical scanning techniques. In forensic contexts, watermark analysis helps determine provenance, confirm authenticity, and support legal proceedings.