Zoom on Spitzer and ISO spectra of class and type sources analysed in the out-of-plane aromatic CH mode’s spectral region. The sources labelled in italics correspond to available Spitzer high-resolution spectra (R ~ 600). Several analogues produced in different ball-milling environments are displayed above, for a direct comparison of the position of the observed bands and a range of measured relative intensities. The typical span of expected positions for the CH out of plane bands according to the underlying aromatic structure to which they are attached are given above (1H: solo; 2H: duo-bay, armchair; 3H: trio; 4H: quartet).