Natural plant fiber covers the non-wood cellulose sources we blend outside the named single-origin materials: sugarcane bagasse, reed, grass, and other agricultural cellulose depending on what the part needs and what is seasonally available. It is the most flexible material in the range, because the blend is tuned to the application rather than fixed by a single source. Fiber lengths sit in the 1.0 to 2.0 mm band, which balances formability against strength.