Random Magic Armor (any level)

A suit of armor or a shield with this enchantment normally has a dull gray appearance. The armor absorbs the first 10 points of acid damage per round that the wearer would normally take (similar to the resist elements spell).
Aura: Faint Abjuration
Caster Level: 3rd
Requirements: Craft Magic Arms and Armor, Resist Energy
Price: +18,000 gp
Source: Dungeon Master's Guide v.3.5