The Historical Role of Photomechanical Techniques in Map Production Karen Severud Cook ABSTRACT: From the 1880s until the 1970s, photomechanical techniques played an important role in map making. Images created by and for photography were manipulated to form the printing image(s) from which the map was reproduced in multiple copies. After experiments in mapmaking in the 1860s, photomechanical techniques gained acceptance by the 1880s and, thereafter, increasingly dominated mapmaking until their rapid decline after the 1970s, as the shift to computers and electronic technology occurred. When they replaced earlier manual methods in the nineteenth century, photomechanical techniques caused the tools and materials of map production and the roles of personnel to change. Control over image production shifted from the printer to the cartographer as pen-and-ink drafting and associated collage techniques developed in the early 1900s, and even more so when scribing came into general use in the 1960s. Having thus assumed more direct responsibility for the end product (the printed map), the cartographer also adopted methods of predicting and controlling its appearance, such as standardized tools and materials, drafting specifications, flow charting, and color proofing. Through the faster and cheaper production of maps whose graphic presentation of information was enhanced by tonal effects and color printing, photomechanical production techniques also contributed to the growth of the map trade and of map use during the twentieth century. KEYWORDS: Photomechanical map production; map design; map reproduction; production tools; production techniques; production materials; pen-and-ink drafting; photographic halftone screen; photographic tint screen; stick-up; negative scribing; technical pens; photolithography; photoengrav- ing; collage techniques Introduction images for and by photography that ultimately form the printing image(s) from which the map is or about a century (from the 1880s until reproduced in multiple copies. They combine the the 1970s), photomechanical production ability of photography to create images automatically played a significant role in mapmak- (by the action of light on a light-sensitive emulsion) Fing. After several decades of initial experimental with the ability of relief, intaglio, or lithographic development in various branches of the graphic printing processes to reproduce multiple copies by arts, photomechanical techniques began to find repeated impressions of the inked printing image use in map production from the 1860s onward. (Nadeau 1990, p. 377). Continuing technical innovations enhanced the Faster, cheaper, and increasingly competitive graphic capabilities and cost effectiveness of graphically with alternative non-photographic photomechanical production techniques until techniques, photomechanical techniques became their use in mapmaking peaked in the 1970s. ever more important in map production from the By that time, advances in computer techniques 1880s until their decline after the 1970s. When they for map production were offering new alterna- replaced earlier manual methods in the nineteenth tives, and the focus of innovation shifted in that century, photomechanical techniques caused a change direction. By the 1990s electronic technology had in the tools and materials of map production and almost entirely supplanted photomechanical tech- the roles of personnel. Through the faster and nology in map production. cheaper production of maps enhanced by halftone As employed in mapmaking, photomechanical effects and color printing, they also contributed to production techniques involve the creation of the growth of both the map trade and map use in the twentieth century. This essay traces the historical Karen Severud Cook is Assistant Special Collections Librarian (Manuscripts) at the Spencer Research Library, University of Kansas, rise and fall of photomechanical techniques in map 1450 Poplar Lane, Lawrence KS 66045-7616. Phone: (785) 864-3357. production and explores their far-reaching impact E-mail: <[email protected]>. on cartography. Cartography and Geographic Information Science, Vol. 29, No. 3, 2002, pp. 137-154 Photomechanical Production in mental data in the form of photographs from the Cartographic Process which point locations, relief, and other map in- formation can be compiled. Although the idea of Map production is but one step in the complex photographic surveying had been suggested in cooperative process by which mapmakers take data 1839, it was not until the 1850s that topographic about the spatial environment and turn it into pub- surveyors began to experiment with ground- lished maps that inform the spatial thinking and level photography. The use of photography in behavior of map users. The cartographic process topographic surveying, especially in difficult is often modeled as a sequence of stages. At each terrain, became accepted by the 1880s. From stage, a different combination of techniques, tools, the 1850s onward, ideas for aerial photographic materials, and personnel interacts to prepare the surveying (from balloons and kites) were also put spatial information for transfer to the next stage. forward but with limited progress until after the The sequence of stages may vary but generally invention of the airplane in 1903. Its develop- progresses from initial concept through data col- ment for military purposes accelerated by World lection, compilation, graphic design, production, War I, aerial photographic surveying also found printing, publication, and use. A change in one increasing civilian use from the 1920s onward. element at any stage of the cartographic process Aerial photographic technology and expertise affects the other elements of that stage and, in developed further during World War II and turn, affects the other stages in varying degrees. replaced ground surveying for most mapping Systematically following changes that occur in the purposes by the 1950s. Since the beginnings of cartographic process over time, as this essay does, satellite photography in the 1960s, remote sens- is a useful approach for studying the history of car- ing has also developed, like aerial photography, tography (Woodward 1974). into a largely separate field of activity of data Map production, the subject of this essay, is the collection, analysis, and interpretation. Aerial stage that turns the cartographer’s rough compilation photography and remote sensing supply both into a ready-to-print image. In the photomechanical raw and processed spatial data and imagery for era this usually meant tracing or otherwise copying a cartography and GIS. compiled worksheet to produce one or more camera- 2. Photomechanical production. In map produc- ready images, the number, form, and sequence of tion, the role of photomechanical techniques is which varied according to the production techniques usually to copy an image from one surface to being employed. Photomechanical techniques in another and often to modify it (by scale change, map production must be considered in relation to reversal, halftoning, etc.). The exposure is the production personnel, their tools and materials, sometimes made by contact printing, sometimes and the nature of the camera-ready images they with a camera. The result may serve as a guide produce. The links between map production and image, a transfer image, or an image for direct the other stages of the cartographic process are also use in the next step. Isolated photomechanical important. For example, the choices of production experiments to produce fine arts and scientific and reproduction techniques made at the preceding illustrations were made in France and England stage of map design influence the appearance and during the 1820s and 1830s. A flurry of innova- cost of the printed map product. tion from the 1850s onward, some within cartog- Rather than discuss all the stages and elements of raphy but even more adopted from commercial the cartographic process, this essay will concentrate art, brought photomechanical techniques into on photomechanical production techniques and general use in map production by the 1880s. their connections with other elements and stages. Thereafter, cartographic use increased over time For example, although photographic technology as new techniques caught on, such as halftone in has been important throughout the cartographic the 1890s, four-color process in the early 1900s, process, only those aspects relevant to map pro- and scribing in the 1960s. When the digital shift duction are discussed in detail. This narrow focus began in the 1970s, the challenge of matching is valid because the cartographic uses of photogra- photomechanical effects and image quality with phy have fallen into three distinct categories: data computer software and hardware caused the recording, photomechanical production, and map transition to computer production to lag behind format. These three categories have developed and that for data collection. Computer graphics functioned separately in cartography, as shown by production has succeeded in cartography, like the historical summaries below. photomechanical production before it, by adopt- 1. Data recording. Photographic data recording for ing and adapting technology developed for the mapmaking usually means collecting environ- graphic arts in general. 138 Cartography and Geographic Information Science Vol. 29, No. 3 139 3. Map format. Photographic technology also affect- knowing its origins. The late nineteenth century ed the