Its a Cordura/Canvas exterior with a vinyl interior.

Pretty similar to a chrome bag, but the vinyl lining is secured to the canvas, instead of being stitched together and being slightly loose like my chrome.

I was going to use bleach, but i was afraid of damaging the vinyl lining and fading out the patches.

The only reason i even care is cause i got the one patch at my first concert when i was 15, bit O" sentimental value there.

I'm going to try a mild bleach tonight and just let it soak.