Same as for Fig. 6 but for 1 nm radius particles, with E_g increasing from top to bottom at the peak of the UV bump (at 4.6 μm^-1). The vertical grey line shows the central position of the UV bump at 217 nm and the vertical, lighter grey bands on either side indicate the full width of the observed UV bump (Fitzpatrick 2004; Fitzpatrick & Massa 2007). The grey squares show the diffuse ISM extinction curve for R_V = 3.1 (dark) and 5.1 (light) from (Savage & Mathis 1979, large squares) and (Mathis 1990, small squares). The grey curves indicate the average galactic extinction, and its variation (upper and lower grey curves), as derived by Fitzpatrick & Massa (2007).