Comparison of the blue wing of six Balmer line profiles (Hα to H8) calculated from ⟨ 3D ⟩ structures (red, solid) and standard 1D structures (black, dashed) for three models from our sequence identified in Table 2. T_eff values are shown on the different panels. All line profiles were normalized to a unity continuum at a fixed distance from the line centre. All spectra were convolved with a Gaussian profile with a resolution of 6 Å to represent typical observations.