Quick Answer: X-Pac is usually the better backpack material when you want a low-stretch, shape-holding laminate with a waterproof barrier built into the fabric. Cordura is usually the better choice when abrasion resistance, a softer hand, quieter movement, and proven everyday toughness matter more than maximum fabric-level water protection. Neither name identifies one universal specification, so compare the exact X-Pac laminate, Cordura construction, denier,...