Copyright help!?

I'm a professional fine artist and have encountered this many times. There is not to my knowledge any physical thing that can be done to prevent print scanning. Having your logo on the front of the image in an area slightly into part of it helps. That way they cant really crop it out without losing part of the picture. Then it will will be obvious if they illegally copy it. I make sure to give people a notice form in layman's terms about copyright laws. Most people are ignorant of the difference between a published print and the image itself. They think if they purchase a copy of it they bought the rights to make copies. Provide a notice explaining that, and the fact that it is a federal law ( it helps to provide the code #'s) good luck.