I know a relation that is thinking of selling on prints of their image based work (eg paintings or photography) onto cd dvd and in physical printed format. They wonder about the likelyhood of anyone printing multiple copies of their work without permission, so I thought I would look for a solution for them. Does anyone know if its possible for work (in an image based file format or not, from disc) to show perfectly on screen, but is automatically watermarked if a print is attempted? If this is possible, what is the most likely file format that may suit this, and is there any programs that may add watermarks to common image based formats without needing photoshop-they must show on any pc ok, but always print with the watermark?

I also wonder if a physical print can be protected by selling their work onto a certain type of photo paper type that gives optimum quality, but is either unscannable, or gives poorer quality if scanned by a third party? I am wondering what this paper format may be, if true.

Thanks for any advice