13/02/2023
Down can be broken into a spectrum of effectiveness. We measure this effectiveness—“fill power”—by how many cubic inches one ounce of down can fill. The typical range is around 450 to 900, with 900 being the warmest and lightest… but also the priciest.
The warmest, lightest down comes at a premium price because it’s sourced from mature geese. This is the best insulator because the high-loft goose down has a very fine construction. Duck down is less fine than goose down and thus is less expensive, but also maintains slightly less loft.
Natural down is also incredibly resilient and—if properly cared for—can be used for many years. However, down has a few *ahem* downfalls: First, down is incapable of efficiently repelling moisture. In fact, it loses many of its insulating properties when it gets wet and is often slow to dry.