Temperatures T_F and masses M_F derived from fitting F_ν of both isolated and embedded protostellar envelopes (with the true masses M of 0.03, 0.3, and 3M_⊙) vs. the true model values of T_M and L for three β values (1.67, 2, 2.4). Results from successful thinbody and modbody fits for various subsets Φ_n of fluxes (Sect. 3.4) are displayed by the colored and gray lines, respectively. See Fig. 6 for more details.