I really like the http://www.chapmanbags.com/men/officers-ipad-bag.html approach to waterproofing. They bond the canvas to a waterproof membrane and so allow the it to retain a natural and more refined look than waxing. The above example was just a quick pick based on your preferred dimensions, but it might be worth your while to peruse the site. They do custom too.
4/23/15 at 6:48pm