Signing prints.

Wondering how many of you digitally sign your prints. I've sold about 30 prints and I go back and forth between signing the print in the lower right corner and signing the mat. Which do you think customers prefer?

I date and sign my stuff in the bottom, right corner on the print. I use an archival pen....no digital signatures.

I never ask a customer WHERE they want the signature. I just ask if they WANT it signed or not.