Canvas has been used since before Christ when cotton was recognised as a commodity that could create tents and covers. It was the Roman Empire that truly evolved this substrate and subsequently any army in the world relied on the creation of Canvas from the Crimea to Gettysburg. Thus the military has always had an affinity to Canvas and its successful weatherproofing and breathable properties.
Defence and the Military has changed but we consistently provide product the MOD whether as an accessory to a tank, an aircraft or on battleships.
Equipment will always need to be protected and particularly electronics.