Same as Fig. 9, but now showing multi-epoch optical spectra. We show the rectified flux F_λ/F_c, where F_c is the continuum flux (each ordinate tick mark is separated by 1). The time origin corresponds to shock breakout (taken to be when the luminosity at the photosphere rises to 10⁴² erg s^-1). All three models show narrow line profiles at the earliest times, but only the models with a dense atmosphere/wind retain this property, for a duration that depends on the density and extent of this external material and the SN shock speed. When spectral lines are primarily electron-scattering broadened, the peak emission is centered on the line rest wavelength. When spectral lines are primarily Doppler broadened, the peak emission is blueshifted, which can compromise a robust identification or lead to an erroneous measure of the redshift if the blueshift is ignored, as in Gezari et al. (2009).