Método no invasivo para la determinación de las filigranas en el patrimonio documental: fotografía infrarroja transmitida (IRT)Non-Invasive Method for the Determination of Watermarks in Documentary Heritage: Transmitted Infrared Photography (TIP)

Abstract

The watermark is an element that is linked to the manufacture of paper and is used to indicate the origin and quality of the paper. In general, it refers to the town and the paper mill where the paper was made. This element is used to date documents and is often not directly observable. Traditionally, different methods have been applied to obtain a clear image of the watermark. These methods can be manual, such as hand drawings by rubbing, but also more sophisticated methods such as phosphorescence techniques or beta radiography. The review of these methods allows us to establish the advantages and disadvantages of their use and to propose a low-cost alternative through the use of transmitted infrared photography (TIP), which provides the recording without damaging the paper support and the reading of the forms without interference from iron-gall inks.