What is the best storage for cartridges?

If you ended up with some cartridges and you do exchange carts on your tonearms what is the most appropriate kind of storage for your carts not used at the time being?

You have not included the 12 carts on the arms.
So the question is a completely different one... :-)

Best @ Fun Only
Dear Thuchan: With all respect I can see that you don't know what to do with your time and money, good looks nice.

I can tell you that several of those cartridges already survived for more than 30+ years ( as mines. ) with out no humidor at all!!

Regards and enjoy the music,
LOL! We have a saying in the U.S., down south. "Well, bless your heart!" :-)
... and that single phrase can be universally translated to mean just about anything.