I've shot a couple of weddings now. Having passed over the 6x4 proofs (which looked really good by the way) the Brides first question was "Am I able to scan them in or are they copyrighted?". Legal issues and the fact that I had standard low res scans on CD anyway aside, how are photographers preventing customers simply scanning in your prints and then trying to print off their own versions using crumby domestic printers or "mini-lab" printers at Walmart\ASDA to avoid paying you cash for proper enlargements from negatives? I have done my best on all occasions to explain how a scan from a print that is then printed will never ever look anyway near as good as a proper pro print from negative but still, I am keen to know for future ref.
I asked my lab if they can add a "Proof Only" watermark and they said they can't - they can only do that when printing digital files with an embedded watermark.
I guess my overall concern is, in the digital age, how are us film photographers protecting our professional product and professionalism and preventing crumby low res scans appearing in frames in our customers homes or workplace? (You can imagine it can't you - a colleague of a customer wants to see a sample of your work and your former customer shows them a dodgy print of their own scan!!)