Preservation of nine bark cloths from the South Sea Islands

15 Jul 2014

Origins of the bark cloths

The nine bark cloths arrived at the museum less than a year ago, when the London Missionary Society (now part of the Council for World Mission) donated a large part of its historic collections to the National Maritime Museum. They are a little different from the ‘usual’ textile objects held in the museum’s collections: bark cloths are made from the inner bark of the mulberry and breadfruit tree species, which are readily available in the region of the South Sea Islands. The cloths were made locally with traditional production methods, and were collected as souvenirs and study pieces in the 19^th century by members of the London Missionary Society. The bark cloths originate from Polynesia. Three of them were collected by missionary John Williams in 1834 from unspecified locations, including the smallest undecorated one and the largest elaborately decorated one which measures some 2200×3630mm. The other six bark cloths came in a bundle in 1896 from Samoa. The thickness of the cloths varies and they all have unique decoration.

Bark cloth making and use

Bark cloths (also called ‘tapa’ in Tahiti and ‘siapo’ in Samoa) were always prepared by women, preferably in the course of one day. To create the cloth, bark is stripped off the tree in one piece, the inner moist layer is peeled away from the outer layer, it is scraped with shells and beaten on a board with wooden or stone beaters to flatten it out and to enlarge its size. Bigger pieces can be made by overlapping the edges of smaller pieces and beating them until they felt together. After the cloth has been stretched and dried under the sun, it is decorated with natural plant dyes by rubbing or painting. (For images on the making of bark cloth in Samoa, follow this link.) Bark cloths were made into garments and masks, and were also used as room dividers, bedding, wrapping for the deceased and even as mosquito nets. Decorated bark cloths were highly valued and were often given as gifts in ritual exchanges. Although the wider availability of woven textiles slowed down their production, in some communities bark cloth is still produced today.

Conservation and preservation process

The nine bark cloths arrived at the Textile Conservation studio folded up in tight packages – this is the usual way of storing ‘siapo’, which unfortunately may cause deteriorated fibres to break. After unfolding them, severe creasing, tears and holes on the less flexible bark cloths became apparent. As rolling is regarded to be the safest option for long-term storage, it was decided that the aim of any interventive conservation treatment would be to enable rolled storage by relaxing the creases and stabilising fragmented areas. The first part of the treatment – smoothing creases – was achieved by introducing humidity back to the fibres in the form of fine cold droplets of deionised water using an ultrasonic humidifier or in other cases a humidity poultice. All of the bark cloths were humidified, but the treatment was tailored to the needs of each item. Stabilising fragmented areas on the most fragile bark cloths proved to be challenging and required consultation between paper and textile conservator colleagues due to the ‘mixed’ characteristics of bark cloths. Even though they are made of cellulosic material similar to linen or cotton, ‘siapo’ cloths have a non-woven texture and do not drape in the same way as textiles but are more similar in flexibility to paper. Besides, a stitched support as a conservation technique must be avoided as it would create permanent holes in the fabric. Conservation literature revealed that up until today, support treatments using patches of fine Japanese tissue adhered with starch paste - a method often used to repair damaged paper - have been most frequently applied for stabilising bark cloths. In our trials the Japanese tissue patches provided a sufficiently strong and visually discrete support. Japanese tissue was torn to the shape of the patches required, and placed onto the reverse of the bark cloth. The patches were adhered with wheat starch paste using small brushes, the areas were weighted and left to dry, and the edges of the patches were trimmed where necessary. The supported bark cloths were then ready to be rolled. After the conservation treatment, the bark cloths were rolled and placed in an environmentally controlled storage space.