Ratio of the carbon-to-oxygen abundances at the end of the TP-AGB phase as a function of the white dwarf mass for Z = 0.0001,0.0005, and Z = 0.001 progenitors – solid, dotted, and dashed lines, respectively. In addition, we show with filled and hollow squares the predictions from our low-mass Z = 0.0001 progenitors in the case that overshooting is considered during the TP-AGB phase and the corresponding results of Weiss & Ferguson (2009) for Z = 0.0005 progenitors.