Guide To Item Upgrades: The Intermediate Guide For Item Upgrades

Path of Exile item upgrades (via Technetbloggers)

Item upgrades are a common and important way to improve the performance of a variety of items in Path of Exile. They can cause additional damage, AD or even affixes.

Sometimes, however upgraded Common and Magic gear is outclassed by Rare-grade gear because of their high requirements.

Armor

Armor upgrades can be applied to both weapon and armor items. They increase the effectiveness of the item upgrader that they're attached to. Armor upgrades can be found in the world of the game and purchased from Blacksmiths on bonfires. They can also be salvaged using a specialist or higher salvage kits to salvage upgrade components from other items.

The amount of damage that an armored item or weapon will absorb is contingent on the degree of upgrades. The ability to absorb damage of a piece armor will increase when it's upgraded to the maximum upgrade level.