Digimark doesn't put an actual visible watermark on the image, it's an electronic watermark that you can check with their online service. For instance, if you digimark a piece and then see it somewhere on a site and want to proove that it's yours, simply point digimark at it and it'll read the electronic watermark and show your name, address and other info that proves without a doubt that the image is your property. That's the beauty of Digimark, no physical watermarking.