X-ray spectral luminosity (left panels) and selected lines zoomed-in (right panels) of ZP96 bubbles with homogeneous WR composition (ω = 0.00, solid/black) and inhomogeneous WR + PN composition (ω = 0.03, dashed/red, and 0.15, dotted/blue). All three bubble models have the same dimension and temperature profile, and the one used in the middle-left panel is the model used in Figs. 14 and 15. The line-profile panels (grey) cover the wavelength range of 0.10 Å each (i.e. the Chandra resolution), but the (logarithmic) ordinate range may be diffferent so as to give a better match to the various line strengths. Also, all lines are normalised to a single continuum level to ease comparison.