UCLA

Baskets are prone to damage caused by the alternate swelling and shrinking of fibers due to fluctuations in relative humidity. At the same time, this sensitivity has long been used to the conservator’s advantage. The chemical composition of cellulose, specifically its ability to form, break, and reform hydrogen bonds, allows for both water and polar solvents to infiltrate, swell and plasticize dried plant tissue. Humidification (or conditioning when using solvents) has become a standard conservation procedure in the re-shaping of damaged basketry in museum collections. However, concerns have been raised over microbial growth, and also the potential for irreversible swelling of the basketry elements. As a result, polar solvents – in this study ethanol specifically – have been added to or become a preferred conditioning media instead of water.

The research for this thesis project, conducted at the UCLA/Getty Conservation Program, revolved around designing an experiment to track the extent of swelling and subsequent recovery of basketry samples made from two woody species treated with water and ethanol vapor. These samples represent two plant species, willow (Salix spp.) and spruce root (Picea spp.), which occur with some frequency in the basketry traditions of the western United States and Canada.

The extent of swelling before and after the conditioning process between all the samples was compared, using measurements taken with a Keyence VHX-1000 Digital Microscope.

The results of this study not only corroborate information from fields as diverse as conservation, forestry science and material science, but also point towards clear trends which can inform the conservator’s decision-making in planning humidification/conditioning treatments of basketry made from woody plant species.