can't add files to usb superdrive media after first recording

Question

iMac 2.9 GHz, 8 GB ram OS X 10.9.5 uses usb superdrive and fails to add files to media after the first refording. Where are the default sessio write or disk write optins and their default values?

Answer 1

Received wisdom would appear to be that the Mac will not natively burn multisession DVDs - nor will it reliably mount them afterwards. (CDs yes, DVDs, no)

It would appear that the only software that will attempt to do this - & then only to DVD+RW is NTI DragonBurn ($32)