Distributions of WD formation time difference (as fraction of the inferred SSE time) in our default model for single WDs from binary mergers. The shaded histogram is the distribution of all WDs in the sample. The coloured lines indicate various types of mergers, as shown in the legend. The black line and shaded grey area show the PDF for all single WDs formed through binary mergers. This also includes types of merger that are not explicitly shown as a separate coloured line.