Classification of antibody (Ab) complementarity-determining regions (CDRs) into canonical clusters. Canonical cluster assignments for all six CDRs were determined from the Protein Data Bank files for each of the Ab:Ag complexes using PyIgClassify 2 (Kelow et al. 2022). The number of times a cluster ID (x-axis) was observed in the structure set was tallied (y-axis) and plotted for each assignment for both the synthetic and natural Ab sets.