Comparison of the integrated intensities found from the models with observations (black circles) normalised to a source distance of 150 pc. Red represents the regions with envelope-only models, and blue shows the regions with envelope-plus-disk models. The smooth regions indicate the models with low mm opacity dust grains, and striped regions show the models with high mm opacity dust grains. The envelope-only models with high mm opacity dust grains and envelope masses of 0.1 M_⊙ and 0.3 M_⊙ are not included here as most of the envelope is photodissociated (Sect. 3.2). Triangles show the upper limits found from observations, and the hollow points are sources with a disk. To explain most of the data, both a disk and optically thick dust are needed.