TY - JOUR
T1 - The use of ground glass in red glazes: structural 3D imaging and mechanical behaviour using optical coherence tomography and nanoindentation
AU - Almasian, Mitra
AU - Tiennot, Mathilde
AU - Fiske, Lionel D.
AU - Hermens, Erma
N1 - Funding Information: The research leading to the nanoindentation results has gratefully received funding from the Koninklijke De Heus/Rijksmuseum Fonds. The research is part of the Imaging, Identification and Interpretation of Glass in Paint project, funded by Netherlands Organisation for Scientific Research (NWO), under the umbrella of the Netherlands Institute for Art, Conservation and Science (NICAS). Partial funding from NSF PIRE (#1743748): Computationally-Based Imaging of Structure in Materials (CuBISM) is gratefully acknowledged. Publisher Copyright: © 2021, The Author(s).
PY - 2021/12/1
Y1 - 2021/12/1
N2 - In this study we investigate the impact of the addition of colourless glass particles to red glazes, as seen in many 15th-17th-century easel paintings. With the use of reconstructions, we examined the influence of the paint preparation process on the morphological and mechanical properties of the paint film. Three sets of reconstructions were made, a control without ground glass, reconstructions with coarse or fine ground glass mixed in, and reconstructions where fine ground glass was ground jointly with the pigment oil mixture. The latter gave the desired consistency and colour based on visual inspection. The dried reconstructions were non-invasively imaged using optical coherence tomography (OCT). A data-analysis pipeline was developed for both the segmentation of the OCT images and the measurement of the size and spatial distributions of the glass particles within the glaze layer. Moreover, we used a nanoindentation protocol to measure the viscoelastic properties of the dried red glaze film. The OCT results show an expected decrease in median particle size with longer grinding-time, for which the additional grinding with pigment/oil resulted in a more narrow size distribution and a homogenous spatial distribution of the glass particles. The nanoindentation results indicate that the addition of glass particles increases the elastic and viscous moduli of the red glaze layers. The homogeneous size distribution, obtained by grinding the oil, pigment, and glass together, induces higher elastic and viscous moduli. Our imaging and analyses approach, combining OCT and nanoindentation, provides a non-invasive and quantitative investigation of glass particles in (semi-) transparent paint layers, and their effect on the mechanical properties of the glaze. The results of this study contribute to a better understanding of the artists’ addition of ground glass in paint layers.
AB - In this study we investigate the impact of the addition of colourless glass particles to red glazes, as seen in many 15th-17th-century easel paintings. With the use of reconstructions, we examined the influence of the paint preparation process on the morphological and mechanical properties of the paint film. Three sets of reconstructions were made, a control without ground glass, reconstructions with coarse or fine ground glass mixed in, and reconstructions where fine ground glass was ground jointly with the pigment oil mixture. The latter gave the desired consistency and colour based on visual inspection. The dried reconstructions were non-invasively imaged using optical coherence tomography (OCT). A data-analysis pipeline was developed for both the segmentation of the OCT images and the measurement of the size and spatial distributions of the glass particles within the glaze layer. Moreover, we used a nanoindentation protocol to measure the viscoelastic properties of the dried red glaze film. The OCT results show an expected decrease in median particle size with longer grinding-time, for which the additional grinding with pigment/oil resulted in a more narrow size distribution and a homogenous spatial distribution of the glass particles. The nanoindentation results indicate that the addition of glass particles increases the elastic and viscous moduli of the red glaze layers. The homogeneous size distribution, obtained by grinding the oil, pigment, and glass together, induces higher elastic and viscous moduli. Our imaging and analyses approach, combining OCT and nanoindentation, provides a non-invasive and quantitative investigation of glass particles in (semi-) transparent paint layers, and their effect on the mechanical properties of the glaze. The results of this study contribute to a better understanding of the artists’ addition of ground glass in paint layers.
KW - Glass in paint
KW - Historical recipes
KW - Nanoindentation
KW - Optical coherence tomography (OCT)
KW - Quantitative data- analysis
KW - Technical art history
UR - http://www.scopus.com/inward/record.url?scp=85107157142&partnerID=8YFLogxK
U2 - https://doi.org/10.1186/s40494-021-00527-y
DO - https://doi.org/10.1186/s40494-021-00527-y
M3 - Article
SN - 2050-7445
VL - 9
JO - Heritage Science
JF - Heritage Science
IS - 1
M1 - 66
ER -