Data treatment AFM images are treated by removing the polynomial background (first or second order) and removing image defects by aligning rows or removing scars using the Nanoscope Analysis and Gwyddion 56 software. The volume data in figure is defined as the bearing volume in the deposited lines, with a threshold value for each pixel set to 2 times the sample roughness. The height data in figure is obtained by taking the average line profile of a written copper wire and fitting a Gaussian to obtain the height and full width half maximum as illustrated in Supplementary file SI-8. The volume in figure is then taken to be the area of this fit multiplied by the length of the path. Fitting was done using the Origin 2017 software.