Formula: Blade oil is an alchemy formula in The Witcher 2: Assassins of Kings that is needed to craft oil.
The formula can first be purchased from Anezka in Lobinden and later from Felicia Cori at Rhundurin Square in Vergen for Iorveth's path and Loc Muinne in Chapter 3.
Note[]
Players have complained that they expected to create something other than the crafting component given the name of this formula, but don't be fooled, this just creates ordinary "oil".