Neutron Activation Autoradiography as a Technique for Conservation Examination of Paintings

Abstract

Conservators of oil paintings are properly concerned with the in depth structures of the paintings they are to treat. A thorough knowledge of the nature and extent of alterations that have occurred within the paintings either through changes made by the original artist, through previous conservation treatment or through deterioration is essential for arriving at a sound judgment as to which parts of the painting should be preserved and how such preservation should be achieved. Areas where the original work lies hidden beneath layers of overpaint laid down in restoration and entire portions of paintings which may be modern additions are obvious cases in point. Painting conservators have for many years made effective use of X-ray radiography, infrared and ultraviolet methods of viewing and of optical microscopy for examination of the structure of paintings. Each of these techniques of examination usually provides useful, pertinent information but each is limited in what it can disclose. Ultraviolet techniques reveal only surface details as does microscopy except in specific regions where cracks, surface losses or the deliberate removal of cross section specimens permits a localized in depth observation. Infrared can reveal some special subsurface details. X-ray radiography, of course, penetrates the painting completely but as