The use of radiography in the examination of corroded excavated metal has become commonplace only during the last decade. While radiography will reveal inlaid decoration, different metals welded together, and depth of penetration of corrosion, it cannot reveal organic materials or very thin platings of metals. Incorrect exposures, poor penetration, and poor orientation of the object will result in meaningless x-rays. Stereoradiography and tomography are technical improvements which result in higher resolution of separate layers and details. See also AATA 20-957 for reference to entire book.