[Archive]

Posted By: davidcycleback

Infrared and x-rays are commonly used on famous paintings to see how the artist worked. What changes were made, etc. In a Rembrandt, they discovered there was a person who was removed from the image. On paintings, infrared and x-rays work the same way, except x-rays sees to a different level of paint.

These techniques are also used to help authenticate old paintings where it is known how a famous painter went about making his paintings (start with a pencils sketch, lawyer the paint this way, make lots of changes, etc). If a painting was constructed from the canvas up the way a famous painter normally constructed his painting, that's evidence it was by the painter. If it was constructed differently than the famous artist would do it, that's evidence it's a fake or by someone else, perhaps his student.

I would guess that nearly all famous Old Masters paintings have been X-rayed. And a collector's statement "I'm off to have my baseball card x-rayed" isn't as insane as it may at first sound.