FSC 100%
All of the material comes from FSC-certified forests.
FSC certified means the wood in a product came from forests managed to Forest Stewardship Council standards, and every company that handled it was certified to keep it separate. In clothing, you'll see it on wood-based fibers like viscose, lyocell and modal, because they're made from wood pulp.
Every FSC label names one of three sources for the wood-based material.
All of the material comes from FSC-certified forests.
A mix of material from FSC-certified forests, recycled material and FSC controlled wood, which FSC uses to lower the risk of wood from unacceptable sources.
All of the material is recycled. FSC says it's still working to extend this label to fashion and textiles.
FSC labels carry a licence code, and FSC runs a public database of everyone who holds one.
Viscose, lyocell and modal are made from dissolved wood pulp. FSC certification covers where that wood came from. FSC says more than half of these fibers still come from uncertified forests.
No. FSC covers the forest and the chain of custody. It doesn't cover the chemistry used to turn pulp into fiber or anything added to the fabric later.
Both certify forests and chain of custody for wood-based materials. They're separate systems with their own standards and labels.