Radiograph

An image produced by radiation other than visible light, especially by x-rays passed through an object or by photographing a fluoroscopic image, on a radiosensitive surface, such as a photographic film. Radiographs are sometimes made of art objects to better see what is beneath their surfaces, in hopes of revealing information about their making, and alterations over time. Typical examples are radiographs of mummies, and of paintings that have been painted over, are in need of conservation, or are suspected forgeries.Also see fluorescence, infrared reflectography (IR) and reflectogram, and overpainting.