Comparison between the measured ¹²CO surface z/r for a sample of disks and their expected values, based on literature total disk mass estimates from dust continuum observations. Black dots indicate the z/r values obtained in this study for our disk sample, open red circles trace the expected z/r values estimated from the dust continuum total disk masses and downwards triangles or shaded areas the expected upper limits or range values of z/r from HD measurements, respectively. The left panel shows the results for a T Tauri system and right panel for a Herbig system. Each horizontal line indicates the z/r of our DALI models with disk masses of 10⁻⁴ M_⊙, 10⁻³ M_⊙, 10⁻² M_⊙, and 10⁻¹ M_⊙, in increasing z/r order, respectively.