For lignin without additives, increasing the grinding time leads to an increase in both surface area and its roughness. However, this effect depends on the reagents used. The samples of the NaOH and SPC/NaOH series are shifted along negative PC 1 values. The influence of NaOH and SPC is mainly described by I2, but anti-correlated. While I2 values increase for the NaOH samples, they decrease for the SPC/NaOH series.