Left: Mg abundances derived from Mg i and Mg ii lines with the 3D model, shown as a function of equivalent width. Right: line-to-line differences between Mg abundances obtained with the 3D and ⟨ 3D ⟩ models, and between those obtained with the 3D and HM models. Filled symbols and solid trendlines indicate lines of the neutral species (Mg i), whereas open symbols and dotted lines indicate singly-ionised (Mg ii) lines. Trendlines give equal weight to each line (unlike our mean abundances, where we give larger weights to higher quality lines).