Comparison between the cumulative distribution of simulated host-galaxy reddening E(B − V) (y-axis) and its approximation (x-axis) given by the best-fit exponential (exp-pdf) or γ-distribution (γ-pdf) model. Each panel in the upper half shows results for four morphological types of simulated host galaxies: LT (with B/T = 0 and B/T = 0.3), S0 type and ET. The columns show three cases of different galaxy-observer orientations: edge-on (left), face-on (middle), and random (right). The bottom panels show analogous comparison for SNe originating from the z = 0 plane of the dust disc in the LT host-galaxy model (B/T = 0). The symbols denote two characteristic scales of reddening with E(B − V) = 0.01 mag (•) and E(B − V) = 0.1 mag (▴), as given by the simulated distributions. The exponential model underestimates the probability of zero reddening, especially in the ET host galaxies. The simulated data are better reproduced by the γ-distribution. For type Ia SNe originating from the proximity of the z = 0 disc plane, the exponential model overpredicts the SN rate with E(B − V)≈0.