Behind the scenes with Conservation
For well over a year now, Conservation teams at the Museum have been working hard to get objects ready for display in the upcoming Citi exhibition: China’s hidden century, which opens 18 May.
Over 200 objects from the Museum collection, from a pearl encrusted snuff bottle emulating a bunch of grapes to tiny embroidered bound feet lotus shoes and even a dried shark’s fin, were assessed for their suitability for display. Many of them went into the Conservation studios for careful cleaning and repair.
Join Organic materials conservators Monique Pullan and Misa Tamura as they reveal three of their favourite objects and the conservation challenges they posed.
Brushwork and patience: work on the straw rain cape
Perhaps the most challenging item was a striking rain cape made from the leaves of the Chinese windmill palm (Trachycarpus fortunuei). Constructed with the long, narrow leaves of the palm arranged in densely overlapping rows, folded over and stitched together, water would have readily run off its surface rather like a thatched roof. The cape would likely have been worn by rickshaw pullers, street cleaners or labourers, often together with a wide brimmed hat, to protect themselves from the rain. Surviving examples of everyday work wear like this are relatively rare.
Probably dating from the mid-to second-half of the 19th century, the palm leaf has become very dry and brittle. Although stored carefully in a lidded box in the Museum’s storage facilities, a bag of collected leaf ends immediately alerted us to its fragility and the fact that any handling had to be done very carefully indeed.
In addition to the fragility of the leaf material, we identified two other areas of concern. Firstly, the cape was covered in fine soot. This needed cleaning, not only for appearance’s sake, but because the sooty deposits are both acidic and a humectant (attracting moisture and mould to the surface) potentially accelerating the breakdown of the leaf in the longer term. This would also hinder any adhesive repairs, with the repair sticking to the dirt and not the leaf surface. Secondly, the cape had become ‘set’ in a flattened, splayed-out position, and would need considerable re-shaping in order to display it as it would have been worn.
Cleaning was by no means a simple or quick task. The leaves could break easily under the slightest pressure or snag on our cleaning brushes. Starting with sable brushes (very soft brushes often used for painting with watercolours) and a low-suction conservation vacuum cleaner, it soon became apparent that the dirt was firmly stuck to the leaf surface and required a different approach. Conservators love creating their own tools, and Misa adapted a block of special hydrophilic sponge into a brush. The sponge-brush was slightly moistened with water and its soft and highly absorbent fingers lightly ‘tickled’ the leaf surface, gently lifting the dirt away. It was a fine balance between the benefit of cleaning against the risks of further damage, with a very patient and alert conservator cleaning leaf-by-leaf. Realistically it was only possible to clean some of the leaves.
Cleaning took place both before and during the process of re-shaping. The stiff cape underwent a series of humidification treatments, with the slow introduction of moisture into the fibres temporarily making them more supple. This enabled the front of the flattened garment to be gradually brought forward and wrapped around a mannequin.
As cleaning and reshaping progressed, Misa was able to address the delicate task of repairing breaks in some of the leaves – the operative word being ‘some’. Early in the treatment, in discussion with the curatorial team, it was agreed that the re-attachment and repair of every broken leaf would not be feasible, and treatment would instead focus on 'almost broken’ leaves, where splits and tears in the leaf could be supported.
She used very thin Japanese kozo (mulberry) tissue paper, tinted light brown, as a repair material. This remains almost invisible when adhered across breaks in the palm leaf strip, both from the front and behind, using a cellulose-based adhesive. The long fibres characteristic to kozo paper (unlike most short-fibred Western made tissue papers) mean that it is strong enough to splint the broken leaf.
Dressing the cape on the mannequin, we came to appreciate how bulky and heavy it would have been to wear. We also discovered how the cape didn’t really have any shaping at the shoulders, with its collar naturally sitting right up under the chin – perfect for preventing the rain from trickling down your neck!
Sadly, pieces of palm leaf will continue to break, particularly when the cape is handled. Ultimately this was one of those frustrating treatments where we as conservators have to accept that the material is weak and degraded and that we cannot reverse this. There will be a degree of loss during the treatment and installation in the exhibition, but this is outweighed by the overall benefit of the cape being seen and studied for the first time in a lifetime.
One of the many joys of working at the British Museum is the opportunity to encounter and share information with people from all around the world. While we were working on the cape, a group of Hawaiian weavers and carvers visited the studio. They were intrigued to see the similarities and differences in the construction of this rain cape and the traditional Hawaiian leaf rain cape, or ahu la’i.
Weaving the straps of the basket carrier
When it goes on display, the rain cape will be accessorised with our second fabulous plant fibre object – a rucksack-style basket carrier. As a basket-lover, Misa particularly appreciated the combination of different techniques used in its construction – from the wicker weave of the main body to the 2/1 twill plait (which creates a diagonal pattern) of the shoulder straps – visualising the skilful hands of the basket-weavers while she was conserving it.
The conservation challenge here was to repair the shoulder straps. Originally designed to bear considerable weight but now more than 180 years old, the leaf material had become stiff and brittle. A perfect example of why conservators always say, ‘never pick up a museum object by its handle’, both straps had completely snapped. The broken ends could luckily be realigned for the most part, but traces of old glue residues indicated that this was not the first time it had broken.
As with the rain cape, Misa again turned to the Japanese kozo paper as her repair material, this time opting for a thicker paper, which she painted and cut into strips emulating the original plant fibre strands. She joined the broken ends of the shoulder straps together by weaving these paper strips into the basketry plait across the break. Preferring to attach her repairs with minimal or no amount of adhesive wherever possible, Misa achieved her repairs primarily through physical interlacing and only required a small dot of adhesive to hold down the ends of each paper strip.
The paper repairs visually blend with the original leaf material in terms of colour, weight, hardness and texture, but remains easily distinguishable upon close inspection – see if you can spot it when visiting the exhibition.