For the sake of having some fun, I'm going to answer this question exactly wrong. Just to get some practice in pointy haired boss thinking. If this isn't appreciated I have no doubt a moderator will delete it and threaten me.
First, have only one person responsible for backups, ever. This way when anything goes wrong you know who to blame.
Next, have the backups out in the open, all over the place, unlabeled as you don't want people to know what they are. You do, and that's enough because nobody really wants to hear about IT security.
Definitely, under no circumstance, should you ever try recovering from these backups. That just eats up company time wasting money.
It's a bad idea to tie up the network by sending backups through it to different locations world wide. And encrypting this just slows everything down. You are wasting valuable resources here buster...
If you feel you HAVE to use encryption, a stream cypher across all those tapes is probably your best option. There are so many free ones to choose from.
Save money and have employees take the tapes home for "off-site" storage.
Save money on backups by using the same tapes for decades.
Forgo backups entirely, this is a 24/7 shop, what leads you to believe we have time to do backups?
Use all the money you saved by following these methods as a reason for why you are spending a gobzillion dollars on data recovery specialists when the time does come...
I mentioned these things only because I've had to stop people from doing them.