As the means of creating the color black have changed, so have the subjects it represents. Suddenly, black was everywhere. It caked the flesh of miners and ironworkers; it streaked the walls and windows of industrial towns; it thickened the smoky air above. Proprietors donned black clothing to indicate their status and respectability. New black dyes and pigments created in factories and chemical laboratories entered painters’ studios, enabling a new expression for the new themes of the industrial age: factory work and revolt, technology and warfare, urbanity and pollution, and a rejection of the old status quo. A new class of citizen, later to be dubbed the “proletariat,” began to…