Pillow Fill Types, Compared by What They Actually Do
Down, memory foam, polyester fibre, and down-wrapped foam each behave differently over years. What changes, and when it matters.
The Calm Finds editorial desk · Published Sep 26, 2026 · Updated Oct 2, 2026 · 7 min
Four fills cover almost everything on sale. They fail differently, which is the useful part — a pillow that feels excellent on day one tells you very little about month eighteen.
Down
Goose or duck down, lofted into a baffle or sewn-in chamber.
- Pro: Exceptional loft for weight, easily reshaped, breathes well, lasts a decade or more if fluffed regularly.
- Con: Loses loft with sustained pressure. The fill power figure is the honest comparison — cubic inches per ounce. Above roughly 700 is a good down pillow; below 600 will flatten noticeably sooner.
The failure mode is clusters breaking up rather than the down wearing out. A pillow that is fluffed nightly still has height in year three. One that is never touched compresses within eighteen months.
Down-wrapped foam
A foam core wrapped in down on both faces.
- Pro: Holds shape through the night, which is why it suits side sleepers — the pillow does not flatten behind the shoulder.
- Con: Heavier and costlier. The foam does not recover the way down does once it has taken a body imprint.
Memory foam
Open or closed-cell foam, usually moulded to a contour or a flat slab.
- Pro: Resists dust mites and mould; returns slowly but does return.
- Con: Can run warm. Slow response means it holds the shape of the previous sleeper, which some find uncomfortable. Rarely washable — cover only.
Memory foam is not a filling so much as a choice about temperature and responsiveness. If you run warm in bed it can work against you all night.
Polyester fibre
Hollow fibre or ball fibre, usually as a loose fill or a bonded block.
- Pro: Inexpensive, washable, hypoallergenic, springy in a way foam is not, and often the most forgiving option for a bedroom used by guests.
- Con: Loses loft faster than down and mats over time. Cheap polyester filling is the first thing to fail.
Which one fails how
| Fill | First sign of ageing | Recoverable? |
|---|---|---|
| Down | Flattened, uneven | Yes — beat and fluff |
| Down-wrapped foam | Foam impression | Slowly |
| Memory foam | Slab dip, warmth | Partly |
| Polyester fibre | Matting, loss of bounce | No |
Loft is a measurement, not a description
A pillow labelled “hotel density” or “medium” tells you almost nothing. What is comparable:
- Loft height in inches, measured uncompressed.
- Fill weight in ounces, which is the more honest figure for durability.
- Fill power, for down only — higher means more volume per ounce.
If a page lists none of these, treat the pillow as a comfort purchase rather than a considered one.
What matters more than fill
Cover material and thread count govern how long the pillow looks good. A 400-thread-count cotton cover outlasts a poly blend regardless of the fill inside.
Loft height matched to your position. Side sleepers need more height than back sleepers; a back sleeper on a very lofty pillow ends up with their neck bent upward. This is the most common reason a good pillow is described as a bad one.
Washable cover, zippered. The single most practical feature on any pillow. Filling is not what needs laundering.
Matching fill to position
Back sleepers do well with medium-loft down or a fibre fill, and less well with very lofty memory foam. Stomach sleepers need a low, firm pillow or the neck ends up hyperextended. Side sleepers want height, and this is where down-wrapped foam earns its price. Loft is the figure that follows from that decision — why loft predicts longevity better than fill does is covered separately, because the two answer different questions.
The remaining variable in a room full of coverings is how things are maintained. A pillow that is fluffed and turned lasts considerably longer than one that is ignored, and the same applies to throws, where how to size a throw and GSM give comparable figures to work from.
Frequently asked
- Do memory foam pillows need to be washed?
- Generally no — most are spot-clean only, and the cover is the part intended for laundering. Check the care label rather than assuming the whole pillow is washable.
- Why does my down pillow feel flatter after a year?
- Down clusters break up with use, and a pillow that is never reshaped loses loft faster. Beating and fluffing redistributes the clusters and recovers much of the height without washing.
- Is a down-wrapped foam pillow better than a pure down one?
- It holds shape better through the night, which matters if you sleep on your side. It costs more and is heavier, and it is not obviously better for back sleepers.