Accurate model stellar fluxes are key for the analysis of observations of
individual stars or stellar populations. Model spectra differ from real stellar
spectra due to limitations of the input physical data and adopted
simplifications, but can be empirically calibrated to maximise their
resemblance to actual stellar spectra. I describe a least-squares procedure of
general use and test it on the MILES library.Comment: 7 pages, 6 figures, accepted for publication in MNRA