Cumulus the Quilt 450

Cumulus the Quilt 450 is an ultralight down quilt from the Polish brand Cumulus, founded in 1989, built on the quilt principle: no insulated underside, since down compresses under body weight and loses its loft anyway. The fill is 450 g of goose down rated at 900 fill power (EU standard), 96/4 down-to-feather ratio, spread across 43 H-baffle chambers that limit down migration and keep insulation even. A comfort rating of −1 °C and limit of −7 °C place it in the three-season category — spring, summer, autumn, mild winter with added layers. Its weight-to-warmth ratio of 92.9 g per degree is solid, not class-leading. Shell and liner use 19 g/m² Toray Airtastic 7D ripstop nylon with DWR, keeping total weight at 650 g. It suits thru-hiking and weekend trips where a light sleep system matters more than deep-winter margin. Being a quilt rather than a mummy bag, it needs an insulated pad underneath, and in colder conditions a hood or beanie helps offset heat loss around the head.