Comparison of the average MAC at 10 K and 300 K with astronomical dust models. The MAC of the “astrosilicates” from (Li & Draine 2001) are calculated using Mie Theory for a 0.1 μm size grain (black), for a log-normal grain-size distribution with a mean diameter of 1 μm for spherical grains (magenta) and for prolate grains (cyan) and for a continuous distribution of ellipsoids (CDE, green). We refer to the text for more details.