Looks like waxed canvas is in this year. Blackhawk! has introduced a series of bags made from 10.10 oz Army Duck Martexin wax canvas. Offered in Earth and Slate colors, the Messenger, Satchel and Rucksack all incorporate hidden pistol compartments. There is also a matching accessory pouch which opens into a stretch nylon pocket for a water bottle or SSE use.
(They are already up under the what’s new category.)