Absorption cross-sections of PAHs in the optical/UV (top) and infrared (bottom) as suggested by Li & Draine (2001, dashed blue), Malloci et al. (2007, dotted green), and this work, with parameters of Table 1 for the ISM (dotted magenta) and for NGC 2023 (full magenta line). For comparison we show the cross-section of Coronene (dash-dotted black).