This backpack used wax, waterproof canvas brush color match with oil wax can be used to do outdoor travel bag. Note: for black wash water interlayer canvas not waterproof but add a computer. Mode of opening and closing: draw string. After using washing water canvas, more with our close to the body, reduce friction, use rise more comfortable. Shoulder belt adopt arc clip cotton material, has a certain burden function. New wrapping material color will be a little lighter Leave many traces of chafed in use process, the longer the time pattern, the more beautiful. Can also be myself with a towel cloth items such as their own continued friction.