Funereal Weapon

Transmutation
Level: Artificer * 1, Cleric */Oracle * 1, Inquisitor * 1, Paladin * 1
Components: V, S, DF
Casting Time: 1 Standard Action
Range: touch
Target: weapon touched or 50 projectiles (all of which must be together at the time of casting)
Duration: 1 minute/level
Saving Throw: Will negates (harmless, object)
Spell Resistance: yes (harmless, object)
  You imbue a weapon with a faint silvery glow that dimly illuminates a 5-foot square. An affected weapon also easily bypasses the physical defenses of undead creatures, ignoring 5 points of an undead creature's Damage Reduction, as long as the Damage Reduction is not DR/epic. For example, attacks with a weapon affected by this spell completely ignore a zombie's DR 5/slashing or reduce a lich's Damage Reduction to DR 10/bludgeoning and magic. You can't cast this spell on a Natural Weapon, such as an unarmed strike. Funereal weapon affects the DR of only undead creatures.