 Lignin is a complex polymer found in plant cell walls that has traditionally been difficult to analyze. However, recent advancements in nuclear magnetic resonance, NMR, technology have enabled researchers to gain a better understanding of the structure of lignin. These advancements include the use of two-dimensional solution state NMR techniques, which provide unambiguous evidence for specific structures as well as quantitative structural information. This has led to a greater understanding of how lignin affects the efficiency of biorefining processes. This article was authored by Run Sang Sun, Ja Long Wen, Bai Liang Xua, and others.