  Puffy disc is a numerical model, expected to capture the properties of the
accretion flow in X-ray black hole binaries in the luminous, mildly
sub-Eddington state. We fit the kerrbb and kynbb spectral models in XSPEC to
synthetic spectra of puffy accretion discs, obtained in general relativistic
radiative magnetohydrodynamic simulations, to see if they correctly recover the
black hole spin and mass accretion rate assumed in the numerical simulation. We
conclude that neither of the two models is capable of correctly interpreting
the puffy disc parameters, which highlights a necessity to develop new, more
accurate, spectral models for the luminous regime of accretion in X-ray black
hole binaries. We propose that such spectral models should be based on the
results of numerical simulations of accretion.
