Dust absorption coefficient per dust mass as function of dust size and material parameters. The black line is identical in every part plot, with parameter values as used in the reference model, our dust standard opacities, see Table 3. The upper two figures show the dependencies on minimum and maximum particle size, a_min and a_max. The lower two plots show the dependencies on dust size powerlaw index a_pow and on the volume fraction of amorphous carbon. 25% porosity and maximum hollow volume ratio are assumed throughout. The two numbers in brackets represent the log-log dust absorption opacity slopes between 0.85 mm and 1.3mm, and between 5 mm and 1 cm, see Appendix D.