Madeline Cawkins, “Paleosolotype: Imaging Soil through Chromatography” 
Mentor: Joseph Mougel, Art & Design 
Poster #131

Salt printing is a historical photographic process in which paper is soaked in a salt solution, then sensitized with silver nitrate, dried, and exposed to ultraviolet light using a negative in contact with the paper to create an image. Related to this is a chromatographic process of visually assessing soil compositions using sodium hydroxide to break down-sampled material and silver nitrate to fix the radiating pigmented compounds drawn across the paper. We adapted the traditional salt print to incorporate a solution of soil sampled from various local and regional sites, using naturally occurring and introduced sources of salt to produce landscape photographs of the locations. The resulting images contain within them the material of the place they depict, toned with different shades of brown that correspond to the components of their representative soil. In addition to these landscape photographs, we are also producing hybrid kallitype/chromatographic images by placing soil samples directly on the sensitized paper and allowing the pigmented particles to be drawn out from the center, creating unique radiating compositions of each site’s soil humus and mineral content that correspond to various industrial, residential, and agricultural sites. The chromatographic quality testing is a relatively inexpensive and accessible method of assessing soil composition, frequently used in locations where more sophisticated laboratory access for soil testing is limited or nonexistent. The simplicity of the process makes it ideal for a community-based project, and we plan to partner with existing outdoor programming across the city during the warmer months of the year.