Heliography for letterpress. Georg Scamoni, chief of the photographic section of the Russian Imperial Printing Office at St. Petersburg, added materially to the progress of the Technographic Arts during this period. He worked out, about 1865, a method of photo-intaglio-reproduction by electrotyping on the metallic deposit which forms the image on the developed collodion plate, after first building this up to a sufficient relief by repeated redevelopment and intensification. [1]. Scamoni realized that the image on the collodion negative was actually in slight relief. He saw that if he intensified with silver and redeveloped he could create a relief sufficiently deep to be electrotyped to produce a printing plate. [2]