Transmutation
Level: Assassin 2, Bard 2, Cleric 2
Components: V, S, DF
Casting Time: 1 standard action
Range: Touch
Target: One suit of armour touched/3 levels
Duration: 1 hour/level (D)
Saving Throw: Will negates (harmless, object)
Spell Resistance: Yes (harmless, object)
As you imitate a clanking noise you brush your hand over the armour you wish to silence. The armour glows softly orange for a moment before the glow fades. A closer look reveals what looks like orange grease in the joints of the armour.
While this spell is in effect, the armour check penalty from the affected suit or suits of armour does not apply on Hide and Move Silently checks. Only wearers proficient in the armour’s use get this benefit when wearing the affected armour. The armour check penalty still applies to other skill checks as normal.
Source: Spell Compendium (Page 125), Complete Adventurer (Page 153)