Bring packs outdoors, they're gonna get dirty. If you carry a bag everyday it's going to change (for the better). Waxed canvas has been used for many years without any washing or cleaning. But if you feel you must clean your bag there's a right and wrong way to do it. Most important is not to overdo it.
The Martexin Original Wax fabric we use is intended to be outdoors and is made to last. But it can't be dry cleaned or washed in a machine. Those processes will strip the wax from the canvas. Just like you wouldn't wash a pair of boots or a leather sofa, you shouldn't wash your pack or bag.
Lightly brush off dried mud and dirt with a brush. Start with plain water for cleaning. Hose it off, gently use a scrub brush, rinse, and let it dry. Less is more. For stubborn spots or stains a mild bar soap, flake soap, or saddle soap may help clean specific areas. Test a small area first.
After several years, if you find the canvas drying out and wish to retreat it, you may re-wax your bag. We offer a wax conditioner right from Martexin, it's their original formula and should be used sparingly. Warm up the canvas and the can of wax a little bit. Sunshine works, so does a hair dryer. Rub a little of the wax conditioner in, apply a little more heat so the wax sinks into the canvas then let it cool and dry. Repeat if necessary but don't overdo it, a little is all you need.
The canvas will develop a patina over time; use will bring out unique character and special qualities in the fabric that no other material could offer. Use your bag for years, it will look different (better) than when it was made. Our reliable softgoods are crafted from traditional materials that have lasted through ages, all are built to be used.
The family behind Martexin Original Wax has been making canvas for seven generations. They know their stuff. Most importantly they say "DON'T baby your Martexin Original Wax, wear it often, it is weather-tough". We couldn't agree more.