Upper row (purple): fits obtained using two stacked slabs. Lower row (orange): fits obtained using a filling factor. The total fit is shown in colour in a solid line. In every panel, we show the same observed EB3 profile in a black solid line. The emission component (dashed line) and the absorption component (dash-dot line) are overplotted. The τ label indicates whether τ₁ has been fixed to a certain value, or it has been free to vary in the inversion, see Table 3.