green / recyclable seating foam alternatives?

I am working on an outdoor chair and looking for alternatives to usual cushion foam. Chair is made out of recyclable / green materials so I am trying to use material for cushion which is also green or recyclable.

Any ideas / links? It does not necessarily need to be foam-like, but it should be relatively soft to sit on.

(I remember seeing some indoor chair made out of layers of felt)

While on this topic - any good green outdoor fabrics info would be great.