In this work a novel micro-fading instrument has been developed that has increased structural stability, hence increasing the portability over previously reported instruments of this type. Using this instrument several new experimental methods have been developed and applied for the investigation of the photosensitivity of painted samples and coloured works of art (with particular focus on the effects of anoxic housing). The colour fading and reversion behaviour of a traditional Prussian blue pigment ground in gum Arabic was investigated for the first time in 0%, 2%, 3.5%, 5%, 10% or 21% oxygen concentrations. Results from this investigation indicated that the previously reported deleterious effects of reduced oxygen concentrations (hypoxia) for Prussian blue may only become relevant at oxygen lower levels (beginning at an hypoxic oxygen level above 2% and below 3.5%). An extension of the investigation to a large sample set of Prussian blues indicated that relatively low concentrations of oxygen (around 5%) may be tolerated by Prussian-blue containing works of art. The novel investigation of the effect of reduced oxygen housing using the microfading technique was extended to a very large varied sample set of traditional watercolour pigments ground in gum Arabic. This new avenue of investigation for the conservation of art work produced encouraging results to overcoming some of the problems of anoxic storage for a wider variety of watercolour pigments. This broad investigation also led to a better understanding of how much light exposure, in and out anoxia, is permissible for different types of watercolour pigments. Incorporating a linear variable filter into the design enabled the investigation of the wavelength dependence of fading of many samples to a greater degree of resolution than had previously been attempted. The wavelength dependence of fading for the samples tested was found to correlate well with the absorption spectra although an exception was found when testing a sample of Prussian blue pigment, where the degree of fading decreased with the wavelength of incident radiation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:629200 |
| Date | January 2011 |
| Creators | Lerwill, A. J. |
| Publisher | Nottingham Trent University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://irep.ntu.ac.uk/id/eprint/227/ |
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