[Fe/H] as a function of stellar mass for the GALAH DR3 stars (panel a) and the LAMOST-LRS catalogue of Xiang & Rix (2022) (panel b). The plots are colour coded according to the logarithm of number density. The GALAH DR3 sample includes stars in both MSTO and subgiant evolutionary stages, while the LAMOST sample only includes the subgiant stars. The red dashed lines plotted in panel (a) mark the visually estimated boundary from panel (b) and show that, in the case of GALAH, a significantly larger number of low-mass stars at higher metallicities (> −0.5) is included.