The European standard EN12934 regulates what a manufacturer may write on the label about the filling of a down duvet. It is not familiar to the general public, but for an attentive buyer it is a reliable compass.
Class I
The standard divides fillings into classes, based on purity. Class I is the highest grade. That means: new down or new feathers from mature birds, with a predetermined minimum percentage of down and a predetermined maximum admixture.
Class II and III
Class II and III are lower grades. There the filling may be less pure, the percentage of feathers higher, and recycled material may be included.
On the label
A good down duvet states its class on the label. A mention of 'new' or 'pure' without class usually means the maker prefers not to bind themselves to a standard. We have worked exclusively in Class I for generations. It is what marks the house, not as a sticker, but as a foundation.