Piscis Noctis wrote:
does this help?

https://www.raymond.cc/blog/signmyimage … signature/

Thanks! 

But these are all computer side for a few images.  I'm looking for something to do it on my websites server when a purchase is made before the images are downloaded.

R_Marquez wrote:
Why not just do some markings like stock photography sites? Anyone willing to steal that is going to steal it no matter what you do.

Very true.  But I happen to have thousands of my images being traded at any given time.  I'm starting to get a bit tired of it.  I'm actually very liberal when it comes to copyrights...  I think the law is silly and only beneficial to major media companies.  It doesn't help the little guy.  I wouldn't mind a person sharing a few of my images here and there... it's quite flattering actually.  But when they share hundreds, sometimes ripping off entire websites worth... then I get a bit pissy.