Schematic behaviour of Ṁ as a functionof L for a hydrogen-free WN star with T_* = 141 kK, based on the series of hydrodynamcially-consistent WN models at Z_⊙ from Sander et al. (2019) and calibrations with the M(L)-relation from Gräfener et al. (2011). The upper dashed line indicates a linear trend in the WR regime, as confirmed from empirical measurements (see text). Lines of R_t = const (L ∝ Ṁ^3∕4, see Eq. (2)) roughly indicate the regions in which a WR, /WR, and Of spectral appearance is obtained. The shaded orange region roughly marks the transition to a WR spectral appearance. We note that the curve and the position of the lines of R_t = const depend on the choice of T_* and X_H, and that the purpose of this figure is primarily illustrative.