Watermarks reflect the very stuff of the origin, date, distribution, composition, history and culture of paper-based items. Digital imaging of watermarks releases the research potential as widely as the internet itself. One example is the digital "fingerprinting" of paper in order to enhance the security of items, such as valuable and vulnerable maps. Revealing Watermarks, by means of the case study of one sixteenth century watermark-a crown from the arms of Danzig-illustrates how cultural influences spread and have endured across the centuries, in this case from Sweden to Russia.