Infrared excess as a function of the UV spectral slope of our galaxies, colour-coded by redshift. Our galaxies are all characterised by very blue β_UV < −1.8 and low IRX < + 0.5. Most of them deviate from the canonical IRX–β_UV relation (solid line; Meurer et al. 1999), and are better reproduced with the bluer intrinsic UV continuum slope β₀ = −2.62 as computed by Reddy et al. (2018) for the SMC (dashed line) and Calzetti et al. (2000) (dotted line) extinction curves.