Evolution of M_dust/M_⋆ as a function of gas-phase metallicities in QGs from this work. The circles are colour-coded by the stellar mass surface densities (expressed on a logarithmic scale). Galaxies are divided into two mass bins: log(M_⋆/M_⊙) < 11 (left) and log(M_⋆/M_⊙) > 11 (right). Brown markers and shaded regions represent the binned medians and 16th–84th percentile range of the resulting distribution for morphologically classified sub-samples of dusty QGs: those classified as eQGs (squares) and sQGs (circles). The typical errors in gas-metallicity estimates for solar and super-solar values are displayed with horizontal lines.