An x-ray image of a canvas painting can reveal the impression left on the ground layer (gesso) by the original canvas, which can otherwise be concealed by paint layers on the front and lining canvas applied to the back. Analyzing the original canvas can provide researchers and conservators with detailed knowledge of the weave pattern, thread count, thread size and direction. Such x-ray images can also reveal distortions from original stretching including cusping near the edges. This information can provide evidence to help determine the approximate date and location of origin of a painting or its artist by comparing the original canvas with canvases of known origin.¹

1. From A. Lui, A. C. Karloff, R. Gr. Maev, Analysis of Painting Canvas Properties by Enhanced Thread Detection in X-Ray Images, Proceedings of the 10th International Conference on Non-destructive Investigations and Microanalysis for the Diagnostics and Conservation of Cultural and Environmental Heritage, Florence, Italy, 2011, p.85.