Research Studentship Working on the Barkcloth Project

My name is Jennifer Brunton and I have recently completed a five-month research studentship on the Pacific barkcloth project, a multi-disciplinary project funded by the AHRC. Working under the supervision of project scientist Dr Margaret Smith and project conservator Misa Tamura, I have been able to expand upon my knowledge of barkcloth, both in terms of scientific analysis and conservation issues. My role focussed on carrying out analysis on cloths through cross-section embedding and polishing for light microscopy, Fourier-Transform Infrared Spectroscopy for molecular identification, X-ray Fluorescence for pigment analysis and optical microscopy to determine morphology.

Colour photograph of Jennifer Brunton, who undertook a five-month research studentship on the Pacific barkcloth project. Here she is using a stereomicroscope to gain a closer view of barkcloth GLAHM E.609 from The Hunterian collection (copyright University of Glasgow)
Using a stereomicroscope to gain a closer view of barkcloth, GLAHM E.609, from The Hunterian collection

Analysis involved sampling barkcloth such as the example below from the Hunterian collection:

Colour photograph showing the lower right corner of cloth GLAHM E.537 from the Hunterian collection. Markers indicate where samples were taken for analysis (copyright University of Glasgow)
The lower right corner of cloth GLAHM E.537 from the Hunterian collection. The markers indicate where samples were taken for analysis

Prior to beginning this studentship, I undertook my MLitt in Technical Art History at Glasgow University. Technical art history places focus on the importance of art technological sources alongside scientific analysis and technical reconstructions. This allows conservators and curators to consider artists’ intent, making and meaning, ensuring the artwork is appropriately conserved, interpreted and accessible to future generations.

Conducting optical microscopy has provided an interesting comparison, and solution, to the problems encountered using cross section embedding to analyse barkcloth samples. I initially carried out cross-section embedding to attempt to understand the application of dyes and pigments applied to the cloths. Cross-section embedding involves taking a small sample from the barkcloth and placing this into resin, afterwards this is cured and polished. This provides an image of a layer structure; however, the difficulties faced with taking good quality cross-sections are visible in the following image.

Colour photograph showing a magnified image of a cross section through a tiny sample from cloth GLAHM E.537, at x 50 magnification (copyright University of Glasgow)
Magnified image of a cross section through a tiny sample from cloth GLAHM E.537, at x 50 magnification

Interestingly, optical microscopy provides a much better image of barkcloth. It provides a visual image of the surface (or reverse) of the material, whereas cross sections capture the object from a lateral perspective. Taking high magnification images also highlights the uneven topography of these cloths; therefore taking stacking images became the most efficient way to look at the surface of the barkcloth. Stacking creates a flattened image of the uneven surface, capturing the whole sample in focus. This is a particularly appropriate way to communicate barkcloth deterioration; in some cases, this has highlighted micro cracking (as shown below.

Colour photograph showing a magnified detail of the cloth GLAHM E.537. Optical microscopy and image stacking reveal extensive micro cracking of the paint structure (copyright University of Glasgow)
Optical microscopy and image stacking (S1, P1, T3) used to examine the surface of the cloth GLAHM E.537

One particular cloth, which has benefitted from stacking imaging, was cloth E537 from the Hunterian collection. This patterned and coloured cloth is thinly beaten and tangibly flexible. From looking at the cloth with the naked eye, it looks in deceptively good condition. However, once a sample had been taken (from sample sites highlighted in figure 1) and optical microscopy and stacking imaging was carried out, it became clear from the extensive micro cracking that the paint structure was under significant stress.

Being able to understand, analyse and appreciate the historical significance of these cloths at first hand has been an invaluable experience and has led me to have a real interest in barkcloth and as a result expand upon my own research interests.