Polarised extinction in the MIR. A composite spectrum (circles) of two Wolf-Rayet stars, WR 48A and AFGL 2104 by Wright et al. (2002), the model (full line) with µm (black) and contribution (dashed) from large amorphous carbon (brown), large silicate grains (green), and dark dust (grey) when treated as prolate particles, as well as the model with µm (blue) is shown. Parameters are the same as in Table 1.