The Witcher 2: Assassins of Kings

Cortinarius is an alchemy ingredient that can be purchased from the following merchants:

• Anezka in Lobinden
• Vilmos Bartok in Flotsam
• Mottle outside Vergen
• Sambor in the camp followers' encampment
• Myron in the Kaedweni camp
• Relic peddler in the Kaedweni camp
• Felicia Cori in Vergen or Loc Muinne
• The Incredible Lockhart in Loc Muinne
• Marcus in Loc Muinne

The Witcher 3: Wild Hunt

Cortinarius is an alchemy ingredient that is needed to craft the following items:

It can be found as random loot, gathered from plants, received from Tomira if she is talked to about Claer after completing Contract: Devil by the Well, or purchased from the following merchants:

• All herbalists except Yolar
• Gremist at Gedyneith
• Jonna in Rannvaig
• Keira Metz
• Merchant at the sawmill in White Orchard
• Generic Merchant in Nilfgaardian Army Group 'Center' Camp
• Merchant at the Boatmakers' Hut
• Merchant southeast of the Border Post
• Merchant in fishing village east of Stonecutters' Settlement
• Merchant in the campsite west of Lurtch
• Merchant at Mire Landing (Cestersover)
• Merchant at a crossroads between Mulbrydale and Devil's Pit
• Merchant by the bonfire at Road to Bald Mountain
• Merchant in the Fish Market in Novigrad
• The Pellar near Blackbough
• Wandering merchants in Velen and Novigrad
• Wandering merchant in White Orchard during the epilogue
• Merchant at Crane Cape