A HISTORICAL MAP-PRINTING TECHNIQUE: WAX ENGRAVING
This article has attempted to bring a lesser-known printing process to the attention of paper conservators because the correct identification of printing technique can be crucial to a successful conservation treatment. Although lithography was the main printing process of the 19th century, other techniques— like wax engraving—were used to make commercially printed material that is now in libraries and museums. The process was used extensively for maps, technical illustrations, business stationery, and other commercial prints but was never an important technique for artists. The lines, symbols, and type in wax-engraved maps established a new cartographic aesthetic that endures today in maps printed using modern printing technologies.
Some characteristics of wax-engraved maps are those of other relief printing processes, but because of the delicacy possible in wax-engraved lines, the characteristics may be very subtle and may be visible only under magnification. The relief print characteristics found in wax engravings are ink squeeze at the edge of lines and plate indentation in the paper. In addition, wax-engraved maps have very uniform lines and symbols, fine parallel lines in colored areas, and very sharp and minute type.
I would like to thank David Woodward, Arthur H. Robinson Professor of Geography at the University of Wisconsin and editor of The History of Cartography, for his generosity. Helena Wright, curator of Graphic Arts Collection; Joan Boudreau, collection manager; and R. Stanley Nelson, museum specialist, all of the Division of Information Technology and Society at the Smithsonian's National Museum of American History, were very helpful. Figures 4, 6, 12, 13, and 15 in this article are of a series of plates in the Graphic Arts Collection at the Smithsonian's National Museum of American History. I am grateful to my supervisor, Martin Burke, for supporting this research.