Duqueyroix, Nadège; Robinet, Laurianne; Barbe, Coralie, “Expandable polyester hinges for parchment mounting performance in fluctuating environmental conditions”, Journal of Paper Conservation 16(1) (2015) 18–28.
DOI:10.1179/1868086015Z.0000000002 (Maney Online)
Abstract:
The high hygroscopicity and heterogeneity of parchment make it particularly sensitive to fluctuating environmental conditions. Due to this, the final housing of an artwork on parchment, including mounting, should aim to mitigate the impact of the fluctuations on the object. The conservation of two navigation maps painted on parchment from the Musée national de la Marine, Paris raised the question of finding an appropriate mounting method. Flexible mounting techniques that adapt to the movement of parchment have been developed by conservators in the past, but their behaviour and efficiency in a fluctuating environment have not been observed or tested. This study focuses on the expandable polyester hinges method developed at the Victoria and Albert Museum and evaluates the safety and performance of this mounting technique in fluctuating environmental conditions. We explore an alternative way of manufacturing reproducible hinges using laser cutting.
The elongation capacity and breaking point of the hinge are assessed. Mounted and unmounted parchment samples are exposed to different levels of relative humidity (RH) (from 9 to 75%), and their dimensions and distortions are recorded and compared. Mounting with expandable polyester hinges maintains the parchment in a reasonably flat condition and prevents the appearance of distortions. At 9% RH, it even seems to restrain the dimensional variations of the parchment. We observe that the more hinges are used for mounting, the more flat the parchment remains. We successfully apply this mounting technique to the two navigation maps. The study demonstrates that the expandable polyester hinge method is safe and efficient in mitigating the impact of humidity fluctuations on parchment.