Blank DVD media are advertised as "printable"; what does this mean?

Yes you need a special printer but its not that uncommon a feature on home inkjets to be honest once you get in to the mid-range models.

Yep, you can print directly on the disc with an inkjet printer. The special feature that you need is basically that the printer is able to feed something relatively small and thick on a straight paper path. Usually there is a trap door on the back to open up so the disc (or stiff card stock) can go straight through instead of turning over some rollers on the way out to the delivery tray.

OIC. Too bad none of my printers is capable of this. :-(

Thank you, jellies!