From ex-situ AFM topogrpahy we determine the deposited volume as a function of the total charge passed through the system, which is controlled by varying either the voltage (1.3 to 2.1 V in steps of 0.1 V, Fig. ) or writing time by means of the translation speed (3, 10, 30, and 100 nm/s, Fig. ). The linear dependence of the volume on charge supports the electrochemical nature of the process. However, the amount of charge required to obtain an equivalent volume of solid copper from Cu 2+ is five orders of magnitude smaller than that derived from the measured current. This suggests that large stray currents are present across the substrate that do not result in copper growth, which is not surprising given the large surface area of our substrate electrode (˜5 cm 2 ). Moreover, Fig. shows that the deposition is suppressed at high currents/potentials most likely due to the competing proton reduction reaction, which leads to a "working" potential window. Actually, the formation of bubbles is observed underneath the tip at higher current densities (typically ˜20 nA ). The additive nature of the fabrication is highlighted by the increase in volume with time when driving the system at a fixed potential. In particular, the volume increases linearly with charge but only after a certain threshold (Fig. , black curve). We attribute the presence of a minimum amount of charge required for growth to kinetic limitations of the nucleation. By contrast, the average height of the deposits (red curve) rises fast right after the threshold followed by a linear increase as a function of total charge. This dependence is indicative of a switch between the isotropic growth characteristic of small clusters (height ∝ V olume Influence of tapping dynamics In the following, we investigate the impact of AFM tapping parameters on local growth to better understand the mechanism of confined electrochemistry. We adjust the tip position dynamics through the peakforce amplitude (PFA) and the force setpoint (FS) parameters (Fig. ). The time-averaged tip-sample distance or gap size (<z>) and time in contact (CT) are estimated from the PFA and FS settings as described in the supplementary file SI-3. The effect of the FS on <z> is quite significant.