Early-, intermediate-, and late-time spectroscopic comparisons of SNe IIb. Phase from the explosion date is given in the legend and all spectra are shown in the rest frame. All spectra have been corrected for redshift and extinction. The key line features are marked, with allowed transitions indicated by dashed lines and forbidden lines represented by dotted lines. Some spectra with lower S/N have been smoothed using a Savitzky-Golay filter.