Left panel: colour excess E(B–V) derived fromSED fitting (A_V∕R_V, Paper I) vs. the value obtained using the observed and the intrinsic colour ; the latter is based on the spectral type reported in Paper I. Right panel: colour excess obtained from A_V ∕R_V, where R_V is estimated using Eq. (1) in Fitzpatrick & Massa (2007), vs. the value obtained by using the observed and the intrinsic colour, as in the left panel. Now the discrepancy between these two values has been removed, demonstrating that the Cardelli et al. (1989) parameterisation underestimates the value of R_V in these sightlines. The blue circles represent the sightlines towards objects with circumstellar disks, the green triangles towards stars with dusty disks, and the black squares towards OB stars.