Diagram: Melltith is a crafting diagram in The Witcher 3: Wild Hunt that is needed to craft Melltith.
It's a possible spawn at a random diagram locations or purchased from the following merchants:
- All blacksmiths in Novigrad, Oxenfurt and Skellige
- Merchant at the Isolated Hut on Hindarsfjall
- Scoia'tael merchant in the Oxenfurt forest