Ranges of gradients for extinction-normalized DIB EWs as a function of β for data from the two catalogues and in various regimes of LOS extinctions. Errors are 1σ uncertainties on the slopes. There are differences at low extinctions due to the very different types of data (individual LOSs vs spatial bins) and at high extinctions due to the small number of data points. Between 1 and 3 magnitudes of extinction, all determinations are compatible and show a negative slope.