Electron backscatter diffraction in conservation science: phase identification of pigments in paint layers

Area of Science:

• Materials Science
• Art Conservation Science
• Analytical Chemistry

Background:

• Characterizing ancient materials in artworks is crucial for conservation.
• Traditional methods often require significant sample sizes, posing risks to valuable artifacts.
• Electron Backscatter Diffraction (EBSD) is a powerful materials characterization technique.

Purpose of the Study:

• To assess the feasibility of EBSD for analyzing heterogeneous paint layers from artworks.
• To investigate the relationship between EBSD pattern quality and material properties (atomic number, density, hardness).
• To demonstrate EBSD's application in identifying pigment phases on real historical samples.

Main Methods:

• Utilized Electron Backscatter Diffraction (EBSD) on micro-samples of paint layers.
• Analyzed reference pigments to correlate EBSD pattern quality with material properties.
• Applied EBSD to cross-sections of paint samples from a 16th-century altarpiece.

Main Results:

• Demonstrated successful EBSD analysis on heterogeneous paint layers, even from very small samples.
• Established correlations between EBSD pattern quality and pigment properties like atomic number and density.
• Achieved, for the first time, EBSD pattern acquisition from resin-mounted painting cross-sections.

Conclusions:

• EBSD is a viable and powerful technique for characterizing ancient paint layers in art conservation.
• This method allows for detailed pigment phase analysis with minimal sampling.
• EBSD opens new avenues for understanding pigment deterioration mechanisms in historical artworks.