What item am I thinking of?

[Darkholme]

I remember someone showing me an item that allows you to prepare additional spell-levels of spell-slots; but can't for the life of me remember what it was called.

Does anyone know which item I'm referring to? (Disclaimer: I think it was a pathfinder item, but it may have been a 3.5 item).

[McBaine]

Ring of Wizardry I-IV doubles the amount of spell slots of the Ring level
(Ring of Wizardry 1 doubles the slots for level 1 spells, Ring of Wizardry 2 doubles the slots of Level 2 spells and so on).

http://www.d20pfsrd.com/magic-items/rings/ring-of-wizardry

[Darkholme]

Hmm. No, that's not the one.

I remember someone pointing out that you could use the 1st level one three times to get an extra third level spell, but it took you longer to prep your spells for the day.

Hmmm.

[Darkholme]

I wish I could remember what the damned thing was called.

[Paulicus]

Ring of Spell-storing? Or was is one of those candles/incense you burn while prepping spells?

[Thanael]

Something with a version for each magical school I think...

[TimD]

Amulet of Spell Cunning, maybe?

-TimD