Spitzer IRS spectra and photometry are presented for the PPNe as in Figure 1 along with the model fits (solid lines). The dashed curves show the assumed underlying continuum in each model. For J051110 the dust radiative transfer program had difficulty in calculating the continuum model and the result shown appears to be slightly inaccurate. In the four cases where an SiC feature is suspected (J050603, J050713, J052902, and F06111), the fits with that feature included are also shown (orange curves in the color version). For object J055311 the best fit obtained using an SiC feature and an amorphous carbon continuum is shown for comparison with the IRS spectrum; the feature at 11 μm does not match the expected SiC feature shape. The fitting for J053632 was even more difficult and no model that might even be considered as marginally acceptable was found; thus no model results are shown for this object.