Li, C. (2008). Light damage of water color drawings and counter strategies [Dissertation, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/182032
Lichtschaedigung von Aquarellen; Bleichung von Wasserfarben; Multibandbeleuchtung mit LEDs
de
Light damage to watercolor drawings; bleaching of watercolors; multi-band illumination by LEDs
en
Abstract:
The quality of paintings and drawings with respect to brightness and spectral reflectivity of their colors is gradually reduced by illumination. The scientific treatment of such problems seems to be an actual challenge in modern museum life. It is important to know which status of aging applies to the single specific art object (for the sake of a critical judgment of the compliance for renting out as well as to clearly observe aspects of conservation and preservation).<br />In this PhD thesis, in cooperation with the Institute of Science and Technology in Arts of the Academy of Fine Arts in Vienna and the Albertina Museum in Vienna, research is done on the objects of Rudolf von Alt (1812-1905). The original water colors are analyzed by a combination of micro x-ray fluorescence (my-XRF), Fourier transform infrared spectroscopy and visible spectrophotometry. Original artifacts of R. v. Alt are analyzed by my-XRF and visible spectrophotometer. With the results, the possible components of the specified color on drawings are identified. Via an artificial aging experiment, the behavior while aging of original water colors is analyzed by visible spectroscopy. With investigation of spectral characteristics and chromatic analysis, the aging level of the colors identified on drawings is estimated.<br />To further protect drawings from photochemical aging in the future, spectrum selective illumination is investigated. With maintaining the brightness and correlated color temperature as condition, it is possible to save irradiation by cutting out part of the spectra. 3-band illumination is a first solution. Nowadays, the more modern and more efficient illuminant, i.e. LED, is considered to compose 3-band illumination. To make such illumination acceptable for museum exhibition, the color rendering ability needs to be enhanced especially.<br />The research shows, that the spectral band centers and band width are very important. Therefore, more than one type of LED is used for each of the 3 bands in simulation and the band centers are optimized. The results turn out to be a multi-band illumination with 4 to 6 bands.
