A process, now obsolete, which was invented by Firmin Gillot (1820-1872), which turned a lithographic plate into a relief plate. A lithographic drawing was made on or transferred to zinc and dusted with resin which acted as a resist. The plate was then etched to make a relief block. An example of a map of Malta by Duvotenay titled Malte printed with this process is found in a c.1866 edition of the Atlas de la Révolution Francaise.
