Science and spectroscopy of cultural artifacts

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Cultural artifacts provide civilization with a historic and artistic record of our past. Cultural artifacts include paintings, archived documents and museum objects that are often made with a very wide variety of techniques and materials. Prior to developing a strategy for conservation or treatment, assessment of the artifact is generally required. Assessment of an artifact can be as simple as a visual inspection or it can involve sophisticated instrumental techniques. This research program is dedicated to the development and application of instrumental techniques that can be used for assisting the conservation scientist in the assessment of a specific artifact. The research program is divided into three areas involving: micro-sampling, multi-spectral imaging and investigating the mechanisms of pigment degradation. The micro-sampling project involves testing the feasibility of using a dry cotton bud for extracting a small amount of pigment from various painted surfaces (e.g. paintings, maps). The most important application for pigment extraction is to identify the metals used in the pigment and since most historically important pigment contain metals, this approach is ideal for identifiying pigments used by artists. Multi-spectral imaging experiments will be directed at artifacts that contain print, which has become faded or difficult to read as a result of natural aging. Specific artifacts that will be examined include a barrel top as well as printed material from the Manitoba Archives in Winnipeg. Part of this research will also focus on the application of mathematical approaches to enhance the readability of faded text. One symptom of ageing of cultural artifacts is a change in appearance such as darkening. Pigment darkening may occur for a number of reasons such as the presence of incompatible pigments or storage conditions. Studies will also be carried out using laboratory prepared paints on microscope slides to investigate the mechanism of degradation of some pigments. Infrared and visible spectroscopy will be used to examine structural and physical changes that occur in the pigments lithopone and the arsenic-containing pigments realgar and orpiment.