Results of Plummer fits to the median radial column density profiles of the filaments in the selected sample with contrasts C⁰ > 0.3 and C⁰ > 1. Panel A: distributions of flat inner diameters D_flat(1) obtained for a fixed value of the Plummer power-law index p = 2 for 260 filaments with C⁰ > 0.3 (black solid histogram) and 113 filaments with C⁰ > 1 (blue dashedhistogram). The median D_flat(1) values are 0.13 and 0.10 pc, and the equivalent standard deviations (estimated from scaling the measured IQRs) are 0.10 and 0.08 pc, for the subsets of filaments with C⁰ > 0.3 and C⁰ > 1, respectively. Panel B: distributions of D_flat(2) values obtained when p is left as a free parameter (i.e., fitting both R_flat and p) for 199 filaments with C⁰ > 0.3 and 79 filaments with C⁰ > 1, respectively. The median D_flat(2) values are 0.15 and 0.12 pc, and the equivalent standard deviations are 0.10 and 0.07 pc, for the subsets of filaments with C⁰ > 0.3 and C⁰ > 1, respectively. (NB: The total number of filaments for which reliable Plummer fits can be derived is lower when p and R_flat are fitted simultaneously than when the fit is performed by fixing p = 2.) Panel C: distribution of power-law index values p(2) corresponding to the D_flat(2) values in panel B. The median p(2) value is 2.2 for both subsets of filaments (with C⁰ > 0.3 and C⁰ > 1), and the equivalent standard deviations of the distributions are 0.4 and 0.3, respectively.