Similar to Fig. 3, but now showing the optical and near-infrared spectra for type II SN models associated with different ZAMS masses from 12 to 25 M_⊙. These models are all characterized by the same H-rich envelope mass of 9 M_⊙ in the progenitor, by weak mixing of non-IGE species (100 km s⁻¹), and by strong mixing of ⁵⁶Ni and daughter isotopes. All models in this set have an ejecta kinetic energy of 10⁵¹ erg and a ⁵⁶Ni mass of 0.08 M_⊙.