Predicted UV and Lyα escape fraction as a function of for the clumpy media studied in Fig. 21 (N₀ = 1 (triangle), N₀ = 4 (circle) and N₀ = 10 (square)). Top: f_esc(UV) obtained from our simulations compared to Eq. (17) used by HO06 to carry out their figure shown in the left panel of Fig. 21. Middle: Lyα escape fraction f_esc(Lyα) predicted by our models for v_exp = 50 km s^-1. Bottom: same as middle panel for v_exp = 250 km s^-1. As in Hansen & Oh (2006), the Lyα escape fraction is derived here at the line centre (i.e. the intrinsic Lyα line is a delta function in our simulations) While a clear decrease in the f_esc(Lyα) with increasing is found, HO06 instead assumes a constant value of f_esc(Lyα), indicated in the figure, independently of the dust optical depth . More precisely, HO06 assumes f_esc(Lyα) = (0.94; 0.68; 0.38) for v_exp = 50 km s^-1 and f_esc(Lyα) = (0.81; 0.43; 0.18) for v_exp = 250 km s^-1.