Not all bags and backpacks of Fjallravel are waterproof, but some of them are made of high-quality natural resources such as their Eco shell-based outdoor products. One of the main ingredients in their manufacturing unit to make their bags and backpacks waterproof is PFC (Perfluorocarbon). Most of the outdoor gears are made of PFC, which makes them water-resistant without hurting nature. Another very famous material type that they use in their backpacks, jackets, and any other outdoor essentials are G-1000. It is a highly rigid and densely woolen fabric that is made of Polyester(65%) and Cotton (35%) that can bear with you in any kind of weather conditions.