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 and jewels 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, Sceptres 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%. |
Adds quality to attached skill |
| 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.
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.