100% Merino wool is a renewable and sustainable resource.  Renewable meaning it can't run out as a resource since it's naturally replaced. It is also biodegradable, organic, and environmentally-friendly. Most often sourced from Australia and New Zealand, the physical properties superfine merino wool has is remarkable. It's hypoallergenic, has antimicrobial qualities (odor resistant,) wrinkle-resistant, thermoregulating, quick-drying (like super quick,) UV resistant, and 6 times stronger than cotton.