Scatter plots of the stellar population properties and quenching timescales of quiescent galaxies on the size–mass plane (left), and M_★/R_e vs. M_★ (right). The panels from top to bottom display stellar metallicity (Z_★), formation redshift (z_form), and quenching timescale (τ_q). The solid red line is the best-fit size–mass relation for the quiescent population. The dashed black lines indicate the 1σ deviation from the best-fit relation. The stellar properties and quenching time were averaged using the LOESS method. Each hexbin contains at least five galaxies. In the top left corner of each panel we show the Spearman rank coefficients (ρ).