Fill power

The loft (English Fill power) is a characteristic measure of down and other upholstery fabrics, indicating which volume assumes a specific mass of the material after a period of compression.

A commercially available unit is the Anglo-American cubic inches per ounce (English cubic inches per ounze, short in ³ / oz or cubic inches for cubic inches ). Is measured by using a ounce ( ≈ 28 g) of down mixture is compressed in the measuring cylinder for 24 hours. Subsequently, the volume is measured to which the sample and stretching ³ inches (1 inch ≈ 16,4 cm ³ ³) stated.

The higher the fill power value, the better the insulation in relation to the packing volume. A high-quality goose down fill power reaches a fill power of 700-800. Commercially 600-700 cubic inches are in good sleeping bags or jackets. Down with less than 500 cubic inches have - at the same mass filling about a down jacket - less bulk - volume ( loft) and correspondingly lower insulation effect.