With Tannery, players can tan premium hides that can be made into unique armor, and be sold to NPC merchants for gems.
Tannery requires a workstation called the Tannery Rack, which can be built as such:
When tanning, there is a small chance that you’ll produce a Masterwork version of the item you’re creating, which will increase additional stats on gear that you make with it!
To learn the details of the Tannery skill, complete the quest “Apprentice Tanner” from Clive in New Nauru, or a Leatherworker citizen in one of your Towns!
Build Guide:
https://mc-atlas.com/model/tannery