A:
The hat is made of a heavy grade of cotton canvas, I think. The brim of the hat is very stiff, and won't flop around, which is one of the main reasons that I wanted it. After it is "broken in", you can bend the brim a little bit to your liking. Done right, it will stay on your head while sitting in the front of a boat going 45 mph..., without a problem!
I wouldn't try to roll it up though. You could push the mesh part down and basically have a dinner plate sized item to put in your luggage.