I always heard to store any ink pad upside down so that the ink is always ready on the surface BUT... did you know that the classic Stampin Ink Pads were designed so that the pad was upside down when closed? So they should be stored with this label facing up.
Now this only applies to classic ink pads. I continue to store my stampin spots, distress inks, and others upside down.
Stampin Up have an excellent storage system for classic ink pads. It holds 48 as well as the re-inkers. There is an extender kit also available should you have more that what the first tier can manage.
So if you feel in the mood to organise your space contact me to order one straight to your door :)