AbstractThis work examined the impact of SuperBatch™ (SB), CompactCooking™ (CC), and Lo-Solids™ (LS) modified kraft pulping on the fiber wall structure of unbleached and bleached unrefined pulps of E. globulus and E. nitens. The kappa number target for all pulps was 17 ± 0.5. It was found that E. nitens had higher water retention values (WRVs) and fiber saturation point (FSP) for both bleached and unbleached pulps versus E. globulus. Fibril lateral aggregates width of unbleached pulps increased as WRV increased. After bleaching there was an inverse trend in correlation of WRV versus the lateral fibril aggregate width. The modified cooking methods or wood species did not have an influence on lateral fibril aggregate width. The higher WRV and FSP values for E. nitens were not reflected in the cumulative pore volume measurements including pore widths below 216 nm.