The Fjällräven Rucksack No21 looks like a classic canvas backpack from decades ago. However it is a modern pack. The base material is G-1000, a combination of 35 % cotton and 65 % polyester. The water resistance can be improved by waxing it. Fjällräven sells his own wax product for this: Greenland Wax. This is made from a mixture of beeswax and paraffin.