Back to projects page © National Museums & Galleries on Merseyside A barkcloth from the Pacific Islands, possibly Samoa, collected by Lord Leverhulme between 1893 and 1911. The mat is circular, approximately 1400mm in diameter, and decorated with black/brown and yellow pigments.	Cleaning a barkcloth mat Annie Lord, Emma Telford, National Museums & Galleries on Merseyside. First published in Conservation News, UKIC, No.64 November 1997
	© National Museums & Galleries on Merseyside The exact history of the barkcloth is unknown other than it was collected by Lord Leverhulme between 1893 and 1911 and comes from the Pacific Islands, possibly Samoa. The mat is circular – approximately 1400mm in diameter – and decorated with black/brown and yellow pigments. Its condition prior to conservation was fair although it was heavily soiled with ingrained soiling, particularly on the more open areas ( ie, where the fibres were least densely packed); it was also creased from previous storage. Cleaning was desirable as it would improve the appearance of the barkcloth for display, reduce creasing and remove unwanted soiling. Tests were carried out to establish the wash fastness of the pigments in water, however, the pigments proved fugitive, even without any mechanical action. Further testing was carried out to see whether organic solvents might provide an alternative solution; Stoddard Solvent [Stoddard Solvent is classified as harmful. Consult safety data sheet before use] proved to be effective at removing dirt and the pigments remained fast even when a swab was rolled over them. Some but not much (we had a tight schedule!) reading around the subject suggested that immersion solvent cleaning was a possibility. Although Ruth Norton [Florian, M., Konkright, D., and Norton, R., The conservation of artefacts made from plant material, The Getty Conservation Institute, 1990, pp. 218-23] suggest that immersion of barkcloth in either an aqueous or non-acqueous solution is not recommended because of swelling of the fibres and pigment loss, she also says that soiling in unpainted areas of barkcloth is not likely to be removed without immersion. Given the success of the initial tests it was decided to proceed.A bath was made on a table placed next to a lab bench with laminar flow extraction. Additional extraction was gained using an ‘elephant trunk’ extraction and a mobile extraction unit. The bath was constructed from wood and polythene into which the barkcloth was rolled from a tube of Melinex.	The barkcloth was cleaned in sections, rolling it form one tube to another. the cleaning process involved three successive baths of Stoddard Solvent, in which the mat was worked over with soft brushes and periodically soaked. Dirt was removed into the solvent with this method and cleaning was suspended after about 2 ˝ hours when no further soiling appeared to be released. It is probable that more would have been removed with further mechanical action, but this was not possible due to the delicate nature of the barkcloth surface. On removal from the bath the mat was blotted with drying papers and some further dirt was removed. The mat was then left to dry flat on filter paper placed over a screen mesh to facilitate air-flow. © National Museums & Galleries on Merseyside After drying overnight the mat was humidified to remove sharp creasing. Firstly the barkcloth was humidified in the humidification chamber for 4 hours. this removed most of the creasing. Remaining creases were dealt with by laying the mat on Gore-tex (non-woven polyester membrane/laminate) which had been dampened on the fibrous side; glass weights were placed on remaining creases. After cleaning, damaged areas were repaired with patches of llens tissue tinted with water colours and adhered with a 50:50 mixture of wheatstarch paste and sodium carboxy methyl cellulose. This mixture was chosen after testing for its combination of strength and flexibility. In conclusion, the solvent treatment was successful in removing a great deal of soiling even thought the visual difference was slight. The reduction and possibly redistribution of soiling could account for the slight loss of contrast between pigmented areas and natural ground colour. This must be weighed against the benefit of removing soiling prior to a humidification treatment. Humidification removed creasing completely and together with the local adhesive application enabled the mat to be rolled safely for storage prior to display. Good extraction was essential both during cleaning and drying.