Canvas is an exceptionally tough, rugged material that can last for years to come when properly maintained and reproofed.
Whilst perhaps most famous for being used in paintings, the tightly woven hemp has endured through the ages due to its ruggedness. This was true even in the art world, as Italian Renaissance artists found the survived the humidity of Venice much better than frescos and wood panels.
Primarily, however, canvas was a sailcloth material, and it is the properties that make a sail effective that also make wax canvas bags hard-wearing in the toughest conditions.
Materials Of The Ancient Mariner
There were several methods used to waterproof clothes, starting with oiled silk umbrellas in China and evolving in a somewhat muddled fashion across continents and civilisations.
The first breakthrough that brought upon the age of sail was the realisation that sails were more efficient when they were wet because the water stopped air from passing through. However, water is heavy and made the boats much slower.
Sailors started to use oils, greases and wax to seal the sails, which stopped them from sagging and getting wet in bad weather and made them more efficient in dry weather.
This principle of waxing canvas came from there, as whilst it does not make canvas waterproof (it will absorb water if it is submerged in it), it does make it weather resistant, meaning that rain will not seep into the cloth. This is important for a bag as it protects everything inside.