Silver Nitrate Development

Silver nitrate reacts with the chlorides in skin secretions to form silver chloride, a material which turns gray when exposed to light. Developed prints must be photographed immediately because the reaction will eventually (and permanently) fill the background. It is useful on paper, cardboard, plastics and unvarnished, light-colored woods. Use it after ninhydrin and iodine. It is not useful on items which have been exposed to water.