Ace Hardware plastic mesh (door screen)
I've bult a small "carpet" of java moss for one of my nano's using plastic door screen mesh and a couple of criss-crossed loops of dark polyester thread. Within a month the moss completely hid the threads and mesh except when my apple snail digs under it and kicks it up, exposing a corner, some underside, etc.
I bought a 1.5 ft X less than 2 ft odd sized scrap of the door mesh for a dollar at my local ACE Hardware. The idea came to me while there shopping for something else.
HOWEVER, I too would sure like to know what the Japanese word is that is being translated in those Amano books so we can know for sure what he's refering to.