I've been using BackupExec for a few years now and don't use the media set process. I choose to set the system to erase/retention the tape and do the backup. This way, like previous comment, if I pick up the wrong one, a backup will still work. I do have two sets of tapes with the Friday always being a different one for every Friday, therefore five Friday tapes. Every other week I swap the set. Also allows the opportunity to swap out a defective tape with ease. Additionally, also use a separate tape for end of month each month.