Spectral differences of IIP and IIL supernovae. The rows correspond to the spectra before and after the continuum normalization. The columns, from left to right: the full sample, the subsample of IIL type supernovae (exhibiting light curve decline rates larger than 1.5 mag / 100 d), and the subsample of IIP supernovae with lower decline rates. The bold colored lines show the medians of the subsamples.