AIC's 46th Annual Meeting

In an ongoing multi-year research project, the American Museum of Natural History, in partnership with Yale University’s Institute for the Preservation of Cultural Heritage (IPCH) and the Peabody Museum of Natural History, is investigating metal-complex solvent dyes as a reversible means for recoloring faded taxidermy. The project has unfolded in three phases. In the first (published in the Pre-Prints of the 2017 ICOM-CC Triennial Conference), accelerated light aging was used to establish the lightfastness of 25 BASF Orasol dyes, as well as selected commercially available equivalent colorants. This testing assessed the performance of dye deposits applied to quartz plate with a solvent carrier but no binding media, an application that is more germane to our recoloring protocol than the manufacturer’s testing of Orasol dyes in polymer resins. This talk will present results of two further complementary phases of the research project, which are intended to evaluate these materials in applications that better simulate object treatment. A key question is whether the lightfastness of the Orasol dyes is impacted by their application to fur substrates, which differ from quartz in their photochemical activity and optical properties. The results of our previous work (described above) enabled us to reduce the number of dyes tested by excluding unacceptably fugitive materials. For this evaluation we applied the selected dyes to fur, exposed the dyed fur samples to accelerated light aging, monitored color change in the samples, and assigned Blue Wool rankings. A second key question is whether the presence of Orasol dye on a fur substrate can be expected to alter the rate of light-induced chemical degradation that fur will undergo in future display. Again, working with a reduced palette of relatively stable colors, fur samples were dyed and subjected to accelerated light aging. Using Fourier transform infrared (FTIR) spectroscopy to probe chemical changes in the fibers, we compared the chemical degradation of the fur in the dyed samples with undyed fur aged in the same conditions. This discussion will benefit conservators charged with the care of taxidermy on exhibit, as well as colleagues in allied fields, in contributing to a more complete understanding of the long-term impact and longevity of treatments using Orasol dyes applied to hair and fur.