You could post images that have been reduced in size that contain a watermark, then allow the user to download the actual purchase image that has been sized according to what they are paying for. It would be up to you to place a small copyright notice (watermark) on the image that the customer downloads, of course advising them if you would be doing so prior to their purchasing. Otherwise, you could show/display the images with watermark copyright, but offer only prints that would be sent to the customer which you could place a copyright notice on the back of (using a soft writing marker that would not dent the print, in a lower corner for example), that way avoiding any marking in the image on the front.
When I sell or gift a framed image or the print, I write my name, copyright, and the year on the back of the print. That way I am noting a copyright on the image/print. I retain my original digital images that contain my name as copyright and other information in the exif data, so if I ever need to prove anything it is easy to do.
Last edited by C_Jones; 10-24-2019 at 03:09 PM.