Bit of advice, if you're going to mark samples, a straight line of a fixed semitransparency is super easy to reverse. Better to use a signature watermark along with a visible mark that isn't as simple, either an irregular shape like text, out irregular colors like a spectrum bar with a few random stretches to make the exact transformation unpredictable.
Might be a little paranoid but eh it's just my two cents on thwarting the jerks of the internet.
Bit of advice, if you're going to mark samples, a straight line of a fixed semitransparency is super
