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Radiography of cultural objects


The radiography of cultural objects is the use of radiography to understand intrinsic details about objects. This process can reveal various details about objects that are not visible to the naked eye. This information, which includes structural elements, aids conservators as they assess object condition and consider treatment plans. Radiography can also reveal previous compositions and earlier repairs.

Infrared and ultraviolet light are also useful tools to understand the intrinsic details of certain objects. However, x-rays tend to be more useful for denser objects. The benefit of radiography is that it is not intrusive. Radiography does expose the object to radiation, but these levels are low. In fact, they are much lower than the radiation levels required for medical x-rays. While technicians and staff conducting the x-ray must use protective gear, the object is not damaged during the process. Furthermore, the use of radiography is widely accepted by conservators, art historians, and archaeologists. Several institutions around the world conduct radiography of objects in their collections including the Victoria & Albert Museum in London, England and the Smithsonian, which operates the Museum Conservation Institute.

Conservators and art historians have used radiography to uncover technical information about paintings. Compositions of materials, previous alterations, and painting techniques have been revealed in x-rays. This data has also been used to date works and identify forgeries. Diagnostic and therapeutic x-ray systems are generally used to produce x-rays of paintings. Infrared reflectography has also been used to see underdrawings and previous markings on painted canvases.

Paints are produced with a variety of elements. Depending on how much these pigments absorb x-rays affects how clear or opaque they will appear in the radiograph, this is known as x-ray fluorescence.Lead white, for example, will absorb more rays and appear much more opaque on an x-radiograph than carbon black, which will allow most of the x-rays to pass through resulting in a clearer result on the radiograph. To produce a radiograph of a painting, the radiographic film is placed on the painted surface and the x-ray tube is placed behind the canvas.


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