Archiving is not intended to keep back ups of your pads.
That's Sync's job

Sync keeps your notes safe on the SharedNote server (you can choose to make the pad public or private). It backs up your pads as you type, you would'nt worry about backing them up yourself.
To activate Sync, open the preferences window and go to the "Sync" tab. You can click on the button to activate your free sync account from there.
Please let us know if this helps