Publication Type:Journal Article
Source:Studies in conservation, Volume 2, Number 4, p.189-191 (1956)
Keywords:examination, paintings, x-ray analysis, x-rays
In an ordinary x-radiograph of an oil painting the difference in absorption of the various pigments makes it difficult to determine radiographically variations in the thickness of the paint layer. A new x-ray method is described which depends firstly on making a solid mould of the surface of the painting in a thermoplastic dental compound. On the impressed surface of the solid mould is poured a thin layer of zinc bromide solution which is then trapped under a thin plastic sheet. The area to be examined is then x-rayed using a dental x-ray machine. It is the thin layer of zinc bromide which is recorded on the radiograph (the plastic mould and sheet being practically transparent to x-rays). Where the surface is very curved or irregular an inflated toy balloon can be used in contact with the zinc bromide solution and held in place by the cone of the dental x-ray machine. In the resulting radiograph the lightest areas represent the highest elevations, the darkest areas the deepest depressions. J.P.