Influence of clumping on the spectral properties of our He-star explosion models. We show the same, unclumped models as in Fig. 4 (black), and overplot the clumped counterparts that use a 50% (blue) and 20% (red) volume filling factor. Each triad of models uses the same normalization, chosen so that the first model in the triad (shown in black) has a maximum flux of unity within the wavelength range depicted. (See discussion in Sect. 7.1.)