The radiography of cultural property is the use of radiography to understand intrinsic details about objects. Most commonly this involves X-rays of paintings to reveal underdrawing, pentimenti alterations in the course of painting or by later restorers, and sometimes previous paintings on the support. Many pigments such as lead white show well in radiographs.

X-ray spectromicroscopy has also been used to analyse the reactions of pigments in paintings. For example, in analysing colour degradation in the paintings of Vincent van Gogh.

These processes 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.

For three dimensional objects, the computed tomography (CT) has become a common tool, which when combined with analysis can, for example, "digitally unroll" or unfold and make possible the reading of fragile scrolls, books, or sealed correspondence.

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.

An X-ray of the Ghent Altarpiece, painted by Jan van Eyck, in Saint Bavo Cathedral in Ghent, Belgium revealed the structure and details of the large altarpiece's painting scheme. The complete radiography of the altarpiece was conducted between 2010 and 2011 as part of a project largely funded by the Getty Institute. The X-rays and other technical information that was gathered were used to prepare conservation treatments.