Absorption (κ_abs; blue) and scattering (κ_scat; orange) opacities from OpTool as a function of the wavelength used in this study. For the calculation of the clump masses in Sect. 3, κ_abs is sampled at Spizer 24 µm and Hi-GAL wavelengths (green dots), and at 1.3 mm (red dot) for the ALMA observations done in SQUALO, which corresponds to the power-law scaling given by the black dashed line, in comparison with the opacity scaling law used in Elia et al. (2017) (black dotted line).