We just found this amazing video of Youtuber Ben, from TheReliableSeries.com, using hot wax to waterproof his Duluth Pack Builders Portfolio. Duluth Pack does offer a waxed canvas version of their bags, however, it is only available in a dark khaki canvas.
This is a great technique to use if you want a waterproof, waxed canvas bag in one of Duluth Pack's other canvas colors. Follow along with Ben's youtube video to see a step-by-step guide to making one of the most durable bags on the market even more durable. Thanks, Ben!