Selected SEDs from τ_V = 50.0 models. The uppermost three spectra are towards the centre of the filament, using the original dust model (black line) or using β = 1.7 dust (blue line) or β = 2.2 dust (red line) in the central part of the filament. The lower spectra (magenta and green) correspond to larger offsets (4.4 and 8.7 arcmin) from the symmetry axis that are not directly affected by the dust modifications. The differences between the measured points and the modified blackbody curves are indicated with vertical arrows. The length of the arrow is ten times the difference between the data point and the fitted modified blackbody curve.