So I am wondering, does anyone out there create extremely durable, frameless, lightweight(relatively) packs? In some situations I would care more about durability than weight. I wouldn't mind a pack being 2.5-3lbs instead of 1.5lbs if it was as tough as a lot of the military packs out there. But by having minimal features and no frame, it wouldn't be 5-6lbs like some packs.
I am thinking about having a pack that would have to handle anything that nature could throw at it, including thorns, shoving through the nastiest, thickest bushes and brush out there, and some occasional rough scrapings on rough rock, and not be replaceable for several years... while still being as light as possible. I know dudes who got Alice Packs when they were teenagers, used the hell out of them, and the packs still going good in their 50s. So it's possible.
In this situation, would someone be better off with canvas, or some kind of tough synthetic? A good, frame less, 35 litre canvas pack might weigh 3lbs. Not bad and they would last longer that you can believe. They become like heirlooms. But would a tough cordura have more durability for it's weight?