Application of the line method to the Sculptor (left) and Fornax (right) dSphs, using the VLT/FLAMES DART dataset. Top panels: distribution on the CaT [Fe/H] versus l.o.s. heliocentric velocity for the stars with S/N/Å   > 10, error in velocity  < 5 km s^-1, and CaT |EW_int − EW_gau| < 2 Å. The black squares with error bars show those stars whose Mg I EW was either lower than or within 1σ_EW from the Mg I EW given by Eq. (1), while gray squares with error bars show those stars whose Mg I EW was more than 1σ_EW larger than the Mg I EW given by Eq. (1). The vertical lines indicate the region of kinematic membership from our previous works. Bottom panel: CaT [Fe/H] versus elliptical radius for kinematic members (black: with Mg I EW within 1σ_EW from Eq. (1); gray: with Mg I EW more than 1σ_EW away from Eq. (1)).