Relation between EW(λ5780.5) and extinction for AM1353-272 (red circles and blue stars). Symbols and colours are as in Fig. 3. Additionally, we show the following Galactic (triangles) and extragalactic (inverted triangles) sightlines: green (Milky Way, Puspitarini et al. 2013); purple (M 31, Cordiner et al. 2011), orange (Magellanic Clouds, Welty et al. 2006), light blue (supernovae, Phillips et al. 2013), black (dusty starbursts, Heckman & Lehnert 2000). We used filled symbols when a galaxy had spatially resolved detections and open symbols when there is a single sightline for a given target.