Bamboo fiber looks promising on a lot of fronts. Dunno about hemp but I can't think of any reason why it wouldn't work. Both are superior to cotton for many things and in many ways. Bamboo and hemp are both far more ecologically friendly, and the only reason hemp isn't cheaper than cotton is that it's illegal to grow in this country and has to be imported. I had wondered about the same thing. I'd think linen (flax) would work too.