Linear combinations of the class A_11.2 profile and a ‘secondary component’ that recover the ‘intermediate’ 11.2 μm profiles of clusters 3 (left) and 2 (right) from the 10.9–11.63 μm wavelength region (see Sect. 5.4 for details). The cluster profile is shown in blue and green in the left and right panel respectively. The dashed purple line represents the scaled class A_11.2 profile given by cluster 4, the dashed orange line is the secondary component, and the bright magenta line represents the linear combination of these two components. We note that the small undulations in the red wing of the profiles are residual fringes present due to incomplete fringe removal.