Creating an item of quality beyond that of Masterwork is possible, but has to requirements:
1. The item must be made of a rare substance.
2. The item must undergo various alchemical processes during creation.
Mithril: Weight cost reduced by half
Armor Max Dex +2, Armor Check lessened by 3.
Weapon Bypass hardness when sundering.
Armor 1DR Light, 2DR Medium, 3DR Heavy. Armor check lessened by 1.