Oil of keen edge
(Player's Handbook v.3.5, page 246)
Price (Item Level): 750 gp (3rd)
Body Slot: —
Caster Level: 5th
Aura: Faint; (DC 17) transmutation
Activation: Standard (applied)
Weight: —
A strange oil with a metalic sheen to it.
Upon applying this oil to a piercing or slashing weapon, it immediately becomes a lot sharper. Double its threat range (does not stack with other effects that double threat range, such Improved Critical feat).
Prerequisites: Brew Potion, Keen Edge.
Cost to Create: 375 gp, 30 XP, 1 day.