Lines: predicted [Fe/H] in the ISM versus time. Shaded region: range of typical observed values from the literature (errors not included). Upper panel: Model 1a (fiducial, solid), Model 1ad (fiducial+dust, dashed). Middle panel: Model 1a (fiducial, solid), Model 2a (WDD1 SNIa, dashed), Model 3a (C-DTT SNIa, dot-dashed). Lower panel: Model 1a (fiducial, solid) compared to Models 4a (dashed), Model 4b (dotted), and Model 5a (dot-dashed) with various SNIa rates.