Comparison of velocity dispersion measurements of the MUSE sample using a range of template libraries. For every pair of libraries, the heat map shows the relative difference in the inferred stellar velocity dispersion, averaged across the sample. The uncertainty is estimated by bootstrap resampling the galaxies. Blue (red) boxes represent pairs in which the library listed on the row yields a lower (higher) value than that listed on the column. The wavelength range is 3600–4500 Å. Comparisons for the KCWI, SDSS, and JWST/NIRSpec samples are shown in Figures A.1–A.3.