Optical Coherence Tomography (OCT) is being used as a tool for non-invasive structural imaging and has been successfully utilized in imaging of varnishes, glazes and underdrawings of paintings, glazes on porcelain and faience, structure of archaic jades, stained and archeological glass, parchment and recently for revealing the surface details of varnished punchwork. The thickness of layers in artwork may be directly measured with OCT in completely nondestructive, quick and convenient way as many times as necessary.  These images can then be utilized for real-time monitoring of conservation treatments, authentication, and evaluation atmospheric corrosion.

Additional general information:

1. Optical Coherence Tomography for Artwork Diagnostics
2. Optical Coherence Tomography in Art Diagnostics and Restoration
3. Optical Coherence Tomography for Non-Destructive Investigations of Structure of Objects of Art 

A 3D rendering of paint layers.

Image of oil painting over sketch made with pencil.