Dust opacities for different maximum grain sizes and compositions. The three panels show, from left to right, dust opacities for a maximum grain size of 10, 100 & 1000 µm, respectively. Each panel contains opacities generated for a mixture of silicates and graphite (0.625–0.375) and a mixture of silicates, graphites and refractory organics (0.627–0.300–0.075; 80% of organics). The gray curve on every panel indicates the albedo of the fiducial composition (silicates and graphites). Four vertical gray lines indicate the observing wavelengths used in this study, corresponding to the observations from Fig. 1. The exact opacity values used in this work are listed in Table 1, for different a_max and compositions, at all four wavelengths.