Light, medium and heavy armor in The Witcher 3
Weight class does more than change the armor number in The Witcher 3. Light armor regenerates stamina fastest and builds the most adrenaline, heavy armor absorbs the most damage and does neither, and medium sits between them. A sign-heavy build and a melee build want different halves of that trade.
Every Witcher 3 armor piece here lists its armor rating, the resistances the game files give it, the level it expects and the slot it fills, so two candidates can be compared without reading them in the inventory screen.
Witcher 3 school gear and everything else
Witcher school sets are built in tiers, and each tier is crafted from the diagram of the one below it. The Witcher 3 gear sets page lays those ladders out end to end; the crafting diagrams page holds the individual recipes.
Relic and mastercrafted pieces found in the world can beat an early witcher tier outright, which is why an armorer is often the better stop before a level-up rather than after it.