Seven-point type is sufficient to get the message across. You may even want to consider printing a separate label which is sure to draw attention. We all know if a client is going to rip you off, they will. Yet a statement like this will at least make the client think a little harder about using your property without paying for it. It will also give a bit more perceived value for your intellectual property, as well as being darn good evidence in a court of law, if it should ever come to that.
Great minds think along similar lines.
We saw the opening announcement in one of those online announce lists about new web sites, so went to take a look. All Rights Reserved. Product names listed are the trademarks of their respective owners.