Average dust mass values, as indicated by the colour according to the colour bar, for bins of different SFR and M_star in different redshift intervals and at all redshifts (upper right panel). Dashed lines represent MS relations of star-forming galaxies as taken from the literature; the local MS is from Peng et al. (2010) (computed using Brinchmann et al. 2004 data), rescaled to a Salpeter IMF, while the relations at higher redshifts are from Santini et al. (2009). Dotted lines represent the ± 1σ (=0.3 dex) scatter of the MS relation.