A digital watermark is a permanent proof of authenticity for an image. While a computer can detect it, it is invisible to the viewer. A watermark contains information about the creator, the copyright, and the image. When a viewer chooses to see this information, the program opens a dialog that contains a link to the Digimarc web page, which displays contact information for the artist.
Important: A layer can contain only one watermark. You cannot embed a new watermark in a layer that already contains one.