(Item/Line): Cuin/Fill Power

CUIN (cubic inches per ounce) aka Fill Power. Fill power is a measure of the loft or "fluffiness" of a down product that is loosely related to the insulating value of the down. The higher the fill power, the more air a certain weight of the down can trap, and thus the more insulating ability the down will have. Fill power is commonly given as a specific volume (the inverse of density), expressed in cubic inches per ounce.