Line-strength dependence for Fe II lines. The profiles (axes at bottom of each frame) and bisectors (tenfold expanded axes at top) are followed through four different models of successively increasing temperature. Two leftmost columns: weak line; two central columns: one of medium strength, with a strong line in the two rightmost columns. From top down: ‘K2 V’, ‘G1 V’, ‘F7 V’, and ‘F3 V’. The long-dashed profiles and bisectors are for disk centers at μ = 1, short-dashed for μ = 0.41, and dotted for near-limb data at μ = 0.09.