Expected plateau luminosity of SN light-curve as a function of the duration of the plateau for our SN IIP progenitor models. Markers indicate models of the same initial mass, and colors indicate different convective core overshooting values. The black-dotted lines indicate typical values of L_p, 0 = 10⁴² erg s⁻¹ and t_p, 0 = 100 days that are calibrated for RSGs with an M_ej = 10 M_⊙, E_expl = 10⁵¹ erg, and R  =  500 R_⊙.