Quality
Quality is a stat that improves the signature stats of an equipment or adds additional bonuses to skill gems. Each item type has a currency item associated with it that increases its quality.
Mechanics
Quality can be applied to most equipment (quivers, jewels, and belts are the exceptions). Any item with at least 1% quality will have a Superior prefix when dropped on the ground but not when in the inventory.
| Item type | Currency | Effect per % quality |
|---|---|---|
| Martial weapons |  Blacksmith's WhetstoneBlacksmith's WhetstoneStack Size: 20Improves the quality of a martial weaponRight click this item then left click a martial weapon to apply it. The maximum quality is 20%. |
1% more Physical Damage |
| Wands and Staves |  Arcanist's EtcherArcanist's EtcherStack Size: 20Improves the quality of a wand, staff or sceptreRight click this item then left click a wand, staff or sceptre to apply it. The maximum quality is 20%. |
1% Gem quality for implicit spell |
| Sceptres | Arcanist's EtcherArcanist's EtcherStack Size: 20Improves the quality of a wand, staff or sceptreRight click this item then left click a wand, staff or sceptre to apply it. The maximum quality is 20%. |
1% more Spirit |
| Armour (equipment) |  Armourer's ScrapArmourer's ScrapStack Size: 20Improves the quality of an armourRight click this item then left click an armour to apply it. The maximum quality is 20%. |
1% more Defence |
| Amulets and Rings | Catalyst | Varies by catalyst |
| Flasks |  Glassblower's BaubleGlassblower's BaubleStack Size: 20Improves the quality of a flaskRight click this item then left click a flask to apply it. The maximum quality is 20%. |
1% more Life/Mana Recovery |
| Charms | 1% increased Duration | |
| Skill gems |  Gemcutter's PrismGemcutter's PrismStack Size: 20Improves the quality of a skill gemRight click this item then left click a skill gem to apply it. The maximum quality is 20%. |
Varies by skill |
For Unique items which grant a skill as an implicit, additional quality will also add quality to the attached skill.
Most items which can have quality can have a maximum of 20% quality. 
Breach RingBreach RingRequires Level 40Maximum Quality is 40%
s can have up to 50% quality. Effects which grant a global increase to gem quality can also exceed this cap.
Quality is multiplicative to affected stats, and is applied after runes and local modifiers.
Amount
The amount of quality given by a quality-increasing currency item depends on the equipment's item level. The higher the item level, the less quality each currency item will give.
Gemcutter's PrismGemcutter's PrismStack Size: 20Improves the quality of a skill gemRight click this item then left click a skill gem to apply it. The maximum quality is 20%.s always add 5% to the skill gem. Corrupting an skill gem may cause it to gain or lose quality, which can cause it to exceed the 20% cap. Support gems cannot have quality added to them.