Fig. 3

SEM images of 1k-PFI refined bleached hardwood fibers treated with different enzyme (E) and cationic starch (S) doses: a Untreated control (0E, 0S); b 0E, 0.5S—increased smoothness; c 0.5E, 0S—increased fibrillation; d 0.5E, 0.5S—increased fiber entanglement. Arrows indicate key morphological changes