Predicted Lyα escape fractions from our 6240 models as a function of E_B − V. Yellow (red) symbols show the simulations with dust-to-gas ratios within a factor 10 (2) of the Galactic value. Among the models with dust-to-gas ratios within a factor 2 of the Galactic value, those with v_exp = 200 km s^-1 are shown by blue symbols. Black symbols show all the remaining models. The blue dashed line shows an attenuation with k_λ = 12. corresponding to the Calzetti et al. (2000) law. Values above this line are due to numerical noise.