Comparison between solar and stellar EW measurements. TOI-1736 and TOI-2141 are shown in the top and bottom panels, respectively. The dashed black line is the 1:1 EWs ratio, and the solid black line is a linear fit based on the Fe I lines, represented by empty black circles. The red star symbols represent the Fe II lines, followed by their linear fit represented by the solid red line. The typical standard deviation of the average linear fit is around ~0.1–0.2 nm, which means ~2% in relative terms.