Functional materials like metals or glasses are formulated into liquid toners that are imaged on a fixed configuration electrostatic printing plate and then transferred across a finite, fluid filled mechanical gap to a variety of substrates. These substrates include glass and metal plates and non-flat surfaces like US coins. Details of this process, the toners formulated to date; and some suggested manufacturing applications are discussed.
Robert H. Detig, "Electrostatic Printing of Functional Materials, a Versatile, Novel Manufacturing Process" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 184 - 186, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00045_1