Finally, we show that columnar morphologies are obtained when scaling the additive concentration with the plating current density in Figure and. Plating is conducted up to a total charge of -7.4 C/cm 2 , both when using 7.5 mM H2O at -0.3 mA/cm 2 , and 75 mM H2O at -3 mA/cm 2 , respectively. Columns are observed underneath large patches of more irregular growth for the former (Figure ), while smooth columns of the expected height are seen for the latter conditions (Figure ). It is worth pointing out that in both these cases the column diameter is much larger than for the conditions used in Figure , such that the samples did not display any bright colors. Furthermore, a poorly directed mossy growth is again obtained when increasing the current density to -3 mA/cm 2 in the electrolyte with 25 mM H2O, shown in Figure , where a more complete sweep of the experimental space is provided in SI-5.