Initial-to-final-mass relation (IFMR) for WDs with the five different metallicities used in this work. Based on the analytic formulae in Hurley et al. (2000) and similar to their Fig. 18. With this choice of metallicity values there is an approximately equal distance between the five lines, so by simulating a stellar population in which the stars have one of these five metallicity values, the effect of metallicity on the IFMR is fully covered.