What fill power actually tells you
Fill power measures how much space a given weight of down occupies. Higher fill power clusters are larger and trap more air, so a 920 fill power comforter reaches the same warmth as a 560 with noticeably less fill inside it. That is why our lightest comforters are also our highest fill power.
The practical difference is weight and drape rather than heat. A high fill power comforter feels like warm air over you; a lower fill power comforter delivers the same warmth with more body and a little more heft. Neither is wrong — it depends whether you want to feel the bedding or not.
Higher fill power clusters also recover their loft better after years of use, which is the quiet reason they cost more.
Warmth weight: match the room, not the calendar
Every one of our down comforter lines is made in three warmth weights, and the ounces of fill scale with the size of the comforter. A queen-size BERNINA 650 runs roughly 24 oz in Summer Weight, 34 oz All Year and 46 oz Winter — same shell, same down, three very different beds.
Most people over-buy warmth. If your bedroom sits at a normal temperature year round, All Year Weight is the honest answer. Buy Winter Weight only if you keep the room genuinely cold, and Summer Weight if you run hot or layer a blanket on top.
The shell matters more than people expect
Down only stays put if the fabric around it is woven tightly enough to be down-proof, which is achieved through weave density rather than chemical coatings. Our comforter shells run from 233 to 360 thread count cotton depending on the line.
Higher thread-count cottons feel cooler, crisper and drier to the touch; the softer weaves feel warmer against skin. Both are down-proof. Baffle-box construction — fabric walls sewn between the top and bottom layers — keeps the down in even chambers so it cannot migrate to the edges and leave cold spots.
- 233–305 thread count: soft, quiet hand; warmer to the touch
- 315–360 thread count: crisp, cool and dry; the finer feel on the highest fill powers
- Baffle-box chambers on every down comforter, so loft stays even
Size up for drape
A comforter that matches the mattress dimensions will be pulled flat between two sleepers and sit short at the sides. Going one size up is the single easiest way to make a bed look and sleep better.
We make comforters from 68x86 through 108x94, and we will confirm your size against your mattress depth and duvet cover before anything is made — tell us the bed and we will do that arithmetic with you.
The four mistakes we see most
- Buying Winter Weight for a heated bedroom, then sleeping on top of it
- Matching the comforter to the mattress size instead of sizing up
- Treating fill power as a quality score rather than a weight-to-warmth ratio
- Skipping a duvet cover — the cover is what keeps the shell clean and the comforter out of the wash