ArGest Backup provides one additional feature to help deter overwriting previously written tapes in the overwrite preference setting “Overwrite tape only if blank”
Tape Overwrite Preference Settings
This setting will not provide an option to continue writing to a tape that is not completely blank when inserted or loaded for the backup or archival operation.
Finally, be sure to label and store your archive job media properly. Do not mix it with your normal backup tapes and definitely keep it away from your blank media.