Conservation teams working on a straw rain cape.

Fabulous fibres for China's hidden century  

By Monique Pullan, Organic Materials Conservation Section, Collection Care

By Misa Tamura, Organic Materials Conservation Section, Collection Care

Publication date: 17 April 2023

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

Cape made of straw.
The rain cape before treatment.

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.  

Conservation team using a brush to work on the straw cape.
Conservator Misa Tamura in action with her sponge brush. 

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.

Clearning the straw cape.
Cleaning the inside of the cape where the wider ends of the folded over palm leaves were located was much easier.

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.

Cape in a humidity tent.
The partially reshaped cape inside a polythene humidity tent. A humidifier pumped cold water vapour into the enclosure, raising the local ‘relative humidity’ to about 80%. The moisture in the humid air was then slowly absorbed into the leaf fibres.

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.

Strand of tissue.
The barely-visible 'bandages' of tissue. 
Fibres and a pair of tweezers.
Conservation team working on the cape.

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.

Conservation team with the cape.
The final stage for Misa and Monique was to prepare the display mannequin with soft cushioning pads, tailor-made to support the shape of the cape. 

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.  

The rain cape, together with hat and basketry carrier, ready for display.
The rain cape, together with hat and basketry carrier, ready for display.

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.

basket continued

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. 

Staying cool with a bamboo bead undershirt

Working on this back in the sweltering heat of July 2022, Monique felt that this bamboo bead undershirt would have been the ideal garment to wear! Made from hundreds of tiny bamboo beads, this long-sleeved garment would have been worn as a man’s undershirt, designed to keep the wearer cool and dry in hot and humid weather by increasing air flow over the skin, at the same time as preventing fine silk outer garments from being stained with perspiration.

Conservation team working on the undershirt.
Monique at work repairing damage to the undershirt.

Meticulously cut from thin bamboo stems, each bead measures no more than 4-5mm long and 2mm in diameter. They are strung together in a diamond-patterned mesh to create the jacket – made entirely in one piece without seams – with fine cotton threads passing through the hollow beads before being carefully knotted at each intersection. Finished off with a thicker cotton edging cord around the scooped neck, front opening and bottom edge, and with tie fasteners, this garment amazes in its elegant workmanship, even though it was never intended to be seen.

Bead shirt.
(L and R) The fact that the undershirt is made of hundreds of tiny bamboo beads can only really be appreciated close up. A decorative band around the waist and at the cuffs has been created by grouping the beads in pairs.

Although generally in very good condition, there were small areas of damage in the mesh, particularly around the shoulders and to the back of the neck. Here broken threading yarn had resulted in holes and, consequently, detached and lost beads. Luckily for Monique, the knotted structure meant that the loss of beads was limited to the immediate vicinity either side of the broken thread.

Close up of threads and beads.
Broken threads and lost beads have resulted in holes and tears in the undershirt. 

In order to repair the damaged mesh and rethread the loose beads, Monique created ‘extensions’ to the short, broken ends of the threading yarn by gluing a length of new thread, similar in colour and thickness, to the stub of the remaining original thread. It was then possible to reattach the beads, using a special ‘twisted wire beading needle’ – a long and extremely fine, flexible needle with a collapsible eye that could be squeezed flat to make it small enough to pass the new thread through the narrow hollow core of the bamboo. 

Thread and pins.
(L) A new thread has been glued onto the broken end of an original one, enabling Monique to re-attach a loose bead. (R) Replica paper beads wound around the shaft of a pin ready for use.

Where they were missing, Monique made replica replacement beads in order to keep the mesh structure stable. She cut narrow strips of paper, 4mm wide, corresponding to the average length of the original beads. These were then pasted with a conservation-grade starch glue and carefully wound around the shaft of a pin to create paper beads matching the bamboo beads in length and diameter. Once dry the paper beads were painted to match the bamboo. This work was time-consuming and fiddly, but certainly enhanced Monique’s respect for the craftsmanship of the original makers. 

Damaged collar and focus on beadwork.
(L) The section of damage at the back of the collar after treatment, secured using a mixture of original and replacement beads. (R) A black mount sets off the beadwork for display.

One aspect of exhibition preparation the public aren’t necessarily aware of is the painful process of needing to refine the list of objects that will be on display, as the design of the exhibition progresses. Conservation work must take place well in advance of the exhibition to meet catalogue photography deadlines.

Sometimes due to alteration in the exhibition narrative, but more usually because there are just too many pieces to fit comfortably or safely into the available display cases, objects painstakingly conserved are cut from the exhibition list. Unfortunately, this was the case with this jacket – although it does feature in the exhibition catalogue China’s hidden century 1792–1912.

You will also have the chance to see it on display in the Sir Joseph Hotung Gallery of China and South Asia (Room 33) from early June, in a small display focusing on bamboo, complementing the exhibition as part of the regular rotation of light-sensitive materials, so the conservation effort is never wasted – and of course any opportunity to stabilise damage is good for the long-term preservation of the collection. 

We hope you have enjoyed joining us ‘behind the scenes’ in conservation, that your appetite for the exhibition is suitably whetted and that you too can begin to share our enthusiasm for these fabulous plant fibres.  

The Citi exhibition: China's hidden century opens 18 May.

Lead supporter Citi.

Additional supporter The Huo Family Foundation. 

This work was supported by the Arts and Humanities Research Council [Grant Number AH/T001895/1].