Comparison of different dust extinction laws which were considered in our modelling of the optical-UV spectrum of NGC 3227. For modelling the internal reddening in the AGN with E(B − V) = 0.45, we use the SMC extinction law of Gordon et al. (2003) with R_V = 4.0 (shown in blue). For foreground Milky Way extinction with E(B − V) = 0.02, we use the extinction curve of Cardelli et al. (1989), including the update for near-UV given by O’Donnell (1994) (shown in black).