I finally got a "Big Bag of Enchantment" pattern and made one for myself. Blizzard has confirmed for me that you can only put DE products in those bags (shards, dusts, essence). This does not include things like elemental essences, elemental cores, etc - things which account for over half of my stack space of enchanting mats. This makes these bags useless. Who is ever going to stock 24 slots of shards, dusts, and essences... especially now with the new stack sizes? I already stock more of these things than most enchanters and my "Big Bag of Enchantment" is only half full. My old "Bottomless Bag" is more useful because it can hold all of my enchanting mats, not just some.