How do you _unset_ the default printer? I know I'm going to hit myself when someone tells me the answer, but I set the Default Printer on my Mac, and wish I hadn't.  Previously, it would default to the last printer used, which was great.  Now I can't find a way to unset the default printer to get back to the last printer used state.

FWIW, I'm on a Mac OS X 10.9.5 - Mavericks.

Command line solutions welcome too...
Go to System Preferences → Printers &amp; Scanners and set Default printer to Last printer used.