There are five levels of Witcher Gear: Basic, Enhanced, Superior, Mastercrafted, and Grandmaster.
Each set has an individual string of scavenger hunts to complete in order to upgrade the gear fully. The collections of Witcher Gear correlate to various witcher schools. These quests serve as maps leading to a set of diagrams, which Geralt can bring to a smithy to craft the corresponding equipment. The other form of upgrading is by tiering up the basic quality Witcher Gear, obtainable through quests known as “Scavenger Hunts.” Scavenger Hunts can be found by chance during Geralt’s travels, or more reliably by buying them from Merchants. They may then choose a compatible piece of equipped gear in which to fasten the runestone or glyph. By selecting a runestone or glyph, some text will appear prompting the player to socket the item.
Runestones and glyphs may only be socketed in gear that is currently equipped. Some weapons and pieces of armor will have sockets on them - indicated by at least one empty circle - in which runestones and glyphs may be fitted. Scavenger hunts can be daunting at first, but as long as you keep track of them as you progress through the game, it’s likely that you’ll find them early, and be able to make the most of them.There are two forms of upgrading gear in The Witcher 3. It’s not necessary to have the entire set to start using these armor pieces, but the stats will be much better if you wear it all together. Keep in mind that while armor sets will get better stats with each tier (and become even more stylish) the cost will be significant.
So, in order to jump from Basic to Enhanced, for example, you’ll need to have each piece of armor either equipped or on your inventory, plus the required materials and crowns. It’s also advised to not get rid of the former set since Geralt can’t create an Enhanced set from scratch. They’re all tied to certain levels, and in order to perform the upgrades, you’ll need to find the corresponding diagrams for each tier. You’ll have to find and talk to Grandmaster Smith in Beauclair, unlocking the grandmaster scavenger hunts. Grandmaster gear is exclusive to Blood & Wine, allowing you to create level 40 versions of each set. The minimum level for this mission is 24. Fergus Graem, located in Crow's Perch, Velen, unlocks the “Master Armorers” quest. In order to unlock the possibility to create Mastercrafted sets, you’ll have to talk with a master armorer. This is due to the different tiers that such sets can be upgraded to: Basic, Enhanced, Superior, Mastercrafted, and Grandmaster.
Once you obtain and craft one of the witcher sets in The Witcher 3, you’ll notice they’re called Basic.