Top: metallicity dependence of M₁₆₀₀–β relation for VANDELS star-forming galaxies at redshifts 2 <  z <  3. The position of the stars (color-coded in metallicity) is representative of the median M_UV and β of the galaxies in each bin. The metallicities (±1σ uncertainty) from the stacked spectra of galaxies in the same bin are written in black on the right side of each star. Single galaxies are drawn with squares. The best-fit relation (red dashed line) is used to divide the bins in β, while mass bins are shown with gray dashed lines. The resulting four bins are marked by 1, 2, 3, and 4. Bottom: Metallicity dependence of M_*–β relation for the same subset of galaxies analyzed in the upper panel. The metallicity is calculated in four bins of stellar mass and UV slope, defined by the dashed lines.