Every year, as the cold creeps in, you dig out your winter wardrobe and reach for that same old coat—it's kept you warm through countless seasons, but it’s definitely seen better days.
Fill weight considers warmth and packability. For example, a 650 down fill jacket with 300g of down can be just as warm as an 800 down fill jacket with 100g down, but the 650 fill will be bulkier.