Notes. i = 0 is face-on and i = 90 is edge-on. The optical depth per cloud is τ_V = 50, and A_V is defined as treated as in Table 2. These models use a mixture of the standard ISM dust composition of 53% silicates and 47% graphites with maximum sizes of 1 μm in the disc, plus a graphite-dominated population of small grains (sizes ≤ 0.25 μm), and large graphites only in the wind (0.75–1 μm). C_T, P_esc, and ${\mathrm{A}}_{\mathrm{V}}^{\mathrm{LOS}}$ as in Table 2, but with ${\mathrm{N}}_{\mathrm{LOS}}(\mathrm{i})={\mathrm{N}}_0{\mathrm{f}}_{\mathrm{wd}}{\mathrm{e}}^{-{((90-\mathrm{i})-{\theta }_{\mathrm{w}})}^2/2{\sigma }^2}+{\mathrm{N}}_0{\mathrm{e}}^{-{(\tan (90-\mathrm{i}))}^2/2{\mathrm{h}}^2}$.