Intensity-averaged linear polarisation fraction (top), maximum polarised intensity (middle) and uniformly smoothed average linear polarisation fraction (bottom) as a function of pivot wavelength for the nine synthetic broad bands, three different inclinations and all six level 3 Auriga galaxies in our sample. The different colours correspond to different Auriga models, while the different lines indicate different inclinations and the different symbols indicate different dust allocation recipes. All models use our reference dust model with f_S, A = 0.6. We note that the HAWC+ E and B-BOP 200 broad bands have very similar pivot wavelengths and are indistinguishable in this figure.