Lignin valorization is hindered by the heterogeneity of its complex structures and variability of biomass feedstocks. Fractionation of lignin can overcome these challenges by producing distinct lignin cuts that can be tailored to end products. This research, published in Bioresource Technology, suggests extracting lignin from poplar via a co-solvent enhanced lignocellulosic fractionation technique, and subsequently fractionate the lignin through solvent extraction and sequential precipitation.