Attenuation on the V band, derived from the BD, as a function of the line-of-sight surface density of the atomic (left panel), molecular (middle panel) and total gas (right panel) mass. Each galaxy is represented by a different colour. The median uncertainties for each galaxy are shown in the top or the lower right corner of the panels. The solid lines are the best linear fits to the full sample, while a shaded area indicates the fit uncertainty. The slope, intercept, and scatter of each fit are also given along with the correlation coefficients.