Use of mock analysis to estimate minimum dust mass that we can actually estimate using our approach. Top: x-axis shows modelled M_dust computed from the best-fit models and for each of our galaxies. CIGALE is able to recover these input dust masses (y-axis) by fitting the mock data down to about log₁₀(M_dust) = 5.0. Parts of the objects in green and all the objects in blue should thus be considered as upper limits. These objects that are the ones identified as transitioners between the upper sequence and a possible lower sequence are well below the prime sequence (red dots). Bottom: log₁₀(M_dust) versus log₁₀(M_star) diagram showing that the lowest dust masses correspond to the lowest stellar masses. However, for the same stellar-mass range, we do observe a wide range of dust masses. Normal, mid, and low M_dust mean M_dust≤10⁵ M_⊙, 10⁵ < M_dust≤10⁶ M_⊙, and M_dust > 10⁶ M_⊙, respectively.