A method and system for masking a surface to be etched is described. The method includes the operation of heating a phase-change masking material and using a droplet source to eject droplets of a masking material for deposit on a thin-film or other substrate surface to be etched. The temperature of the thin-film or substrate surface is controlled such that the droplets rapidly freeze after upon contact with the thin-film or substrate surface. The thin-film or substrate is then treated to alter the surface characteristics, typically by depositing a self assembled monolayer on the surface. After deposition, the masking material is removed. A material of interest is then deposited over the substrate such that the material adheres only to regions not originally covered by the mask such that the mask acts as a negative resist. Using such techniques, feature sizes of devices smaller than the smallest droplet printed may be fabricated.