Overall attenuation curve at ages of 10⁷ yr (dot-dashed, i.e. 0.5τ_esc), 5 × 10⁸ yr (dashed, i.e. 10τ_esc), and 10⁹ yr (solid, i.e. 20τ_esc), we include age effects and plot the value in units of the attenuation in the visible band (λ_V ≈ 5500 Å). We note that these values correspond to the blue, green and red lines of Fig. 8. Our attenuation curves are compared with Calzetti-like attenuation curves (dotted) for different values of the total-to-selective extinction ratio R_V in the V–band (colour-coded).