To determine the processing conditions for optimal lignin extraction, we need to narrow down the Pareto front to a single point by imposing a constraint. For instance, we might accept a slightly smaller yield of say 60%, in return for a higher β-O-4 content. We can then determine from Fig. that this trade-off results in 17.5 β-O-4 linkages per 100 Ar and can be achieved by extracting the lignin at (P f , T ) = (1227, 210 • C).