(( Name pending ))
A grey, large tome with intricate carvings on the outside of a thin sheet of lead. Unlike a normal tome, the sheet encases all sides of the book,which can be opened by the ceremonial lock that normally holds the two halves together.
Opening the lock and swinging the tome open reveals a host of pages, seemingly ever expanding. Each page painstakingly enchanted to never rip or break.
Through specific rituals, energy from spells can be captured in the fibre of the pages, up to a certain potential energy amount. This energy can later be unleashed in specific ways captured in the book.
Myriad Pages: The Tome of Reservation never has too few pages, nor ever too many, it has precisely enough whenever needed.
For the purposes of scribing spells, if the lock is closed and opened again there is enough new space to scribe new spells. Writings that are not spells disappear after the spellbook is closed. Normal costs of scribing spells still apply.
Spell repository: In a bare room with flat surfaces and no other distracting enchantments, a ritual can be performed. Spending 5 minutes, an arcane prepared spell can be channelled into the Tome of Reservation to store its power. In order to do this, the spell must be scribed in the Tome of Reservation, in the handwriting of the caster who executes the ritual.
If the notation has not been made by the caster, then the ritual will fail.
The storing ritual is not lossless, and a great deal more power must be put in than can ever be gotten back. If a particular spell has been stored {3} times, enough energy has been stored to recreate the spell in full. The caster can caster can cast the spell by opening the tome to the right page and triggering the spell. All attributes, including casting time are as if the caster had cast the spell.
A caster can extract a number of spell levels per day this way equal to {their caster level}. Meaning if the caster is 10th level, they can extract 2 5th level spells, or 3 3rd level spells and a 1st level spell.