What a wool duvet is

A wool duvet is layers of wool batting sealed in a cotton shell and stitched so the wool stays spread across the bed. Sellers also call it a wool comforter or a duvet insert.

What is inside a wool duvet?

Layers of carded wool batting, a woven cotton shell around them, and the stitching that holds the two together.

Washed wool is carded into a thin web and laid down layer on layer to build the batting. The batting is sealed in the shell and held in place by hand tufts, sewn channels or quilted boxes. Sleep & Beyond, for example, uses a box quilted pattern to keep its wool batting in place (Sleep & Beyond). Our guide to how a wool duvet is built goes through each part and what to ask a seller about it.

Is a wool duvet the same as a wool comforter?

Yes. Duvet, comforter and duvet insert name one product, and the word you use depends on where you live.

Woolroom says as much on its own product pages (Woolroom). American listings tend to say comforter or insert, and British ones say duvet.

How warm is a wool duvet?

Warmth follows the weight of wool spread over each square yard, not the name on the label.

One maker's range shows the spread. Woolroom rates its 200 gram per square meter fill for rooms of 68°F and up (Woolroom), its 350 gram fill for rooms of 60 to 68°F (Woolroom) and its 500 gram fill for rooms of 48 to 60°F (Woolroom). Our wool comforter buying guide explains how to compare fills across sellers.

Can a wool duvet be washed?

Most cannot. Water, warmth and agitation felt untreated wool, and felting cannot be undone.

Woolmark describes the felting of wool as irreversible (Woolmark). The few wool duvets sold as machine washable use wool treated at the mill, and their labels say so. Our guide on why most wool duvets cannot go in a washing machine covers the rest.