Fluxes at 6.3 μm as a function of Ṁ_g/ ν_∞,g. The data points are color coded according to the method with which the 6.3 μm flux was measured: from ISO data in red, and interpolation of photometric data points in blue. The full and dashed lines are fluxes calculated from models. The red lines represent models with ψ = 0.005, while the black line shows models with ψ = 0.001. The dashed line makes use of a blackbody spectrum of 2400 K for the central star, while the full lines use a COMARCS spectrum. The 6.3 μm fluxes are scaled to a distance of 100 pc.