Individual values of stellar population parameters of quiescent galaxies as a function of their size and median circularised radius (r_c and , respectively) at 0.3 ≤ z <  0.5. From top to bottom: mass-weighted age, formation epoch, metallicity, and extinction for EMILES+Padova00 models. Each panel comprises a different stellar mass range. Vertical bars enclose the 1σ uncertainty level of individual values. Solid lines show the linear least-squares fitting to the distribution of values in each panel (see Eq. (2)), whereas the shaded region is its 1σ level uncertainty. Coloured markers illustrate the smoothed values obtained with the LOESS method (see Fig. 1).