Quality Levels (highest to lowest.)
Bonuses to hit, dmg and AC stack with enchantment bonuses.
Bonuses from quality levels do NOT stack with other quality bonuses. eg a Masterwork bow firing masterwork arrows only gets +1 to hit, not +2.
Very Fine: Only attainable with special materials that offer a quality level bonus. You cannot go higher than this without magical enchantments or ancient tech.
Masterwork: Best attainable quality with normal materials and smithing methods. Weapons and armor of masterwork quality craftsmanship become very fine with certain materials.
Normal: As per rulebook. Normal weapons and armor of this craftsmanship level become masterwork with certain special materials.
Poor: Poorly taken care of or crafted standard items. Also equivalent to bronze age weapons and armor.
Very Poor: Extemely poorly crafted and maintained equipment. Also equivalent to stone age weapons.
Weapons
Very Fine: +1 to hit & damage; +20% to range for missle weapons.
Masterwork: +1 to hit; +10 % range for missle weapons.
Poor: -1 to hit & damage; -10% range
Very Poor: -2 to hit & damage; -20% range
Armor
Very Fine:-2 armor check penalty; +1 AC
Masterwork: -1 armor check penalty
Poor:+1 armor check penalty
Very Poor: +2 armor check penaly; -1 AC
Special Materials
Admantium (Adamantite) (Rare)
Armor: +1 quality level; Damage resistance
Weapons: +1 Quality level; +1 to hit
Mithral (Rare)
Armor: +1 Quality level; Spell Failure -10%; Max Dex +2; Armor Check penalty -2; -50% weight; Reduces armor level by one step (Heavy becomes Medium, Med becomes light)
Weapons: +1 quality level; -50% weight; counts as magic for bypassing damamge resistance
Elysian Steel (Very Rare) - Alloy approximately 50% mithral admantium. Only Elysian Elves know how to create it.
Armor: +1 quality level; -25% weight; spell failure -5%; max dex +1; Armor check penalty -1; Damage Resistance
Weapons: +1 quality level; -25% weight
Darkwood (Blackwood) (Rare) - Strong, lightweight wood found in ancient forests.
Shields: -50% weight; +1 quality level; -1 armor check penalty; -5% spell failure
Bows: +1 quality level; +5% range (stacks with quality level); +1 mighty for masterwork bows, +2 mighty for very fine bows
Cold Iron (Rare) - Mined in the Underdark. Usefull against Fey.
Armor & weapons: +1 quality level
Alchemical Silver (Uncommon) - silvered weapons; usefull against were-creatures and others.
Weapons: -1 damage
Dragon Hide (Very Rare) - Created from the hide and scales of a slain dragon
Shields: +1 quality level; +1 AC; +1 save vs dragon breath per dragon type
Armor: +1 quality level; +1 AC; Elemental Resistance per dragon type
Quicksilver (Mercurial) (Uncommon) - Steel blade with a resevoir of Mercury inside
Slashing Weapon: Critical is doubled (eg x2 becomes x4)
Need exotic weapon feat to use weapon without penalty. Additional -2 to hit in additon to -4 if not proficient.
Fiendish Green Steel (Very Rare) - Mined on the outer planes
Slashing/Piercing weapons: +1 quality level; +1 damage; +1 Crit threat range (eg 19-20 becomes 18-20. Does not stack with keen weapons)
Bludgeoning weapons: +1 quality level
Abyssal Iron (Very Rare) - Mined in the Abyss
Slashing/Piercing Weapons: -1 quality level; poison (primary dmg d2 Con; Secondary d4Con; Fortitude save DC = d20 roll to hit.)
eg the d20 to hit roll shows a '15' on the dice the DC is 15.
Poison works on each hit and stacks with previous hits.
Celestial Truesteel (Very Rare) - Mined on the celetstial planes
Weapons: +1 quality level; +1 to roll to confirm crit; +1 to dmg.
Armor: +1 quality level
Scaymore Silk Cloth (Very Rare) - Only known maker is in Feltrest. Is created by an enchanted/trained beatle which spins silk
Cloth armor: +1 quality level; Self cleaning and repairing due to beatle; DR 5 against piercing and slashing weapons.
Elven Leafweave (Very Rare) - Created from the leaves of Darkwood trees using an ancient Elven secret
Cloth and Leather armors: +1 quality level, -5% spell failure, +1 max Dex; -2 armor check penalty
Bronzewood (Rare) - A wood that is nearly as strong as steel. Found in ancient elven forests.
Plate armors (breastplate, banded, splint, half plate): +1 quality level; -10% weight; -1 AC; armor check penalty does not affect hide checks in woodland environs
Weapons: -10% weight; -1 dmg
Astral Driftmetal (Very Rare) - Mined on the Astral plane
Armor: +1 quality level; 25% chance to work against an incorporeal attack
Weapons: +1 quality level; 25% chance to hit an incorporeal creature as if it was not incorporeal.
Other (non weapon/armor) Special Materials
Drow Spider Silk - Created in the Underdark by the drow. A very silky material that absorbs light and sound well. Unfortunately sunlight causes it to deteriorate. It also makes excellent swimwear since it glides thru the water.