Chinese paintings on Pith – A Paper Conservator’s Approach
Ruth Prosser
魯絲. 普瑟爾 

Pith paper or ‘Rice Paper’ is cut from the inner pith of Tetrapanax papyrifer, a shrub native to Southern China and Taiwan. Its pith has been used for many centuries in China for the making of decorative flowers and as a diuretic in traditional medicine. In the early years of the 19th century, Chinese artists adopted it as a painting support specifically for paintings produced for western buyers. Initially these paintings were brought back by Western visitors such as diplomats and seamen as souvenirs of their travels. However, by the end of the century paintings on pith began to dominate the Chinese export watercolour market. They were brought to the West in great numbers, usually bound in silk covered albums. Pith paintings can be found therefore in many collections all over Europe and USA, both in specialist collections as well as in many larger and national galleries and museums.

Pith paper and conventional paper are both derived from plants but there are significant differences in their chemical composition and structure. These differences are reflected in the characteristics of these two materials. Pith has a soft, spongy texture and is somewhat translucent. It splits easily, particularly on ageing. More significantly, it has been noted that, compared to conventional papers, pith expands and contracts in an extreme way when moisture is applied to it. Being essentially watercolours, the paintings are usually treated by paper conservators and this reaction to water has proved problematic.
This talk will give an outline of the history and methods of production of this unique material but will focus on the nature of pith in the context of practical conservation treatments.

Ruth Prosser, Independent Paper Conservator

Ruth Prosser is an accredited paper conservator with over twenty years experience of working in the public and private sector. She trained at Gateshead Technical College, has a B.A. (Art History) from the University of East Anglia and an MSc in Paper Science from Manchester University. As an independent conservator, she has worked on an extensive private collection of pith paintings and has researched the history, production and nature of pith. In 2008 she gave a talk on Chinese Paintings on Pith in conjunction with an exhibition at the National Arts Club, New York. She has given further presentations on the subject to members of the public and museum professionals in Philadelphia, York, London and Edinburgh and has published two articles about the production and conservation of pith paintings. She has also provided advice and information for an undergraduate research project into the structure of pith at the University of York.