The library where I work recently purchased a set of five copper printing plates produced by the United States Geological Survey in the early 20th century. Three of the plates were used to print city maps. The other two were used to print the details of topography and waterways along with the city maps. The plates are 17″ x 21″ (43 x 53 cm) and quite heavy.
With the plates lying flat on a table under overhead lighting, their appearance changes as you walk around the table. At different angles, the light emphasizes either the finely etched lines in the plates, or the bright, shifting colors of the copper’s surface and the traces of ink and other chemicals.
With two alternate lighting setups, I captured two distinct views in the photography studio.