You can create a VTR archive on a tape that already contains material or add material to an archive on a tape. For example, on a 60-minute tape, you could allocate 20 minutes to an archive by setting its start timecode at 01:00:00:00 and defining the length of the archive as 20 minutes in the Length field. See Creating a VTR Archive. You can then add any material, starting after 01:20:00:00.