In the context of a DFG-funded project, a collaborative German watermark information system was created in order to provide and assemble digitized images of watermarks from different sources, together with metadata on motifs, places of writing, carrier manuscripts etc. WZIS created a standard for the structure and management of a collaborative digital watermark collection and makes it accessible to academic users in online access. The Bavarian State library contributed image scans of rubbings and tracings of watermarks, which were taken in different projects from the 1990s, as well as digital photographs of watermarks in incunabula, taken by a thermographic camera. The tracings and rubbings of watermarks were taken from manuscripts in the holdings of the Bavarian State Library, but also of other Bavarian libraries (including the university libraries of Augsburg and Eichstätt, and the Germanisches Nationalmuseum in Nuremberg). Extensive documentations of watermarks were created in the context of different cataloguing projects, e.g. the Latin manuscripts from the Benedictine monastery of St. Emmeram in Ratisbon, the Latin manuscripts of Augsburg provenance, as well as the BSB’s Greek manuscripts and the illuminated manuscripts from Germany. As part of a project for the digitization and cataloguing of about 90 block books in Bavarian collections, all watermarks were photographed by means of thermography and were ingested to the WZIS database.