Fig. 1. FE-SEM micrographs: on the left side commercial cellulose starting materials: softwood sulfite pulp fibers (a), wheat straw pulp fibers (b), refined fibrillar-fibrous
wheat straw pulp (c), refined beech wood pulp powder (d), and refined fibrillar-fibrous beech wood pulp (e). On the right side mechanically, laboratory isolated nanofibrillated
cellulose out of the stated starting materials. From ref.