The main difference between these wools comes down to sourcing and certification. Premium Eco Wool is sourced from the Pacific Northwest, while Certified Organic Wool is sourced from New Zealand, where they can produce the quantity we need. Both wools are vetted to make sure the farms are ethical to both the sheep and the workers, sustainably managed, and that the sheep are raised in a chemical free environment. They are even processed in the same facility with the same gentle biodegradable soap! That said, the GOTS certification of our certified organic wool requires audits to ensure their standards are met, and they have the paperwork to track down to the specific sheep your wool came from.