Example of fitting of a Lyα profile to estimate the influence of a blend on the three profile characteristics. Observed data are plotted with stars, while the resulting fitted profile (including blends) is plotted as a thick full line. The Voigt function fitting the profile in the wings is plotted as a thin solid line and the negative Gaussian in the profile reversal as a dashed line. The blend occurring at approximately 1025.5 Å was fitted with the Gaussian and is plotted in red.