Conservation Department

Textile conservation

The journey continues: stain removal and washing of Asian textiles

While most of us don’t think twice about throwing our clothes into a washing machine and letting technology and optical brighteners do the work, textile conservators take a slightly different approach. Stain removal and washing are complex procedures, requiring an understanding of the chemical and physical reactions that occur between textile components and aqueous solutions and solvents.

Many Asian textiles that have been collected in the field are often extremely dirty and discoloured. Stains not only interfere with the design of a textile but also contain harmful elements that cause the deterioration of fibres. The conservation policy at the Gallery is to preserve and stabilise works of art while trying to retain as much of the artist’s original intent. For the exhibition Sari to Sarong: 500 years of Indian and Indonesian textile exchange stain removal and washing are an important part in the conservation treatment of the textiles selected for display.

One of the first treatments carried out on all textiles is vacuuming. Although this sounds relatively harmless, along with washing, it is one of the more physical treatments undertaken. Dirt, dust, pollen, vegetable matter and fluff is collected on a filter, which can be analysed at a later date. Vacuum samples often provide information on what sort of life a textile has led: where it has been stored or displayed, whether it has been near sooty oil lamps or draped in dirt, wrapped over food, or used as a funerary cloth.

Once vacuumed, if the textile is still dirty or discoloured, the dyes are tested with possible solutions for stain removal and washing. If any dye loss is noted then the textile is unable to be fully immersed and a different treatment approach is thought out, which may be a partial treatment of only the stained areas or no cleaning treatment at all. Stain removal techniques vary depending on the types of stain, so a variety of aqueous solutions or drycleaning solvents are used. Not all stains can be removed but most can be reduced in some way. Solutions are applied with cotton buds and blotters are placed underneath the textile to collect the flushed out stain. After this textiles that have fugitive dyes or components that cannot be washed are ready for any physical repairs.

All of the Indian textiles made of cotton selected for the exhibition Sari to Sarong will have undergone some form of washing, from spray rinsing through to full immersion in soap solution followed by rinsing. These textiles are generally made of strong cotton with relatively stable dyes. The majority have some form of brown liquid staining and a yellow/brown discolouration attributed to the natural degradation or oxidation of the cotton fibres. A few have problems with the mordents used in the dyeing process which have caused weaknesses in the cotton. These areas are notably more acidic and, where possible, the acidic products are flushed out. Some of the Indonesian textiles, on the other hand, are more varied, with components of metallic threads or with dyes that are fugitive. These cloths can not be fully immersed, so only spot treatments are carried out on various stains.

The conservation department manufactures its own soap solution comprising an anionic detergent base plus other dirt removing substances. It does not contain any of the harmful bleaches or optical brightening agents found in the commercial washing detergents. The solution is generally used at less than 1% and the wash bath temperature is monitored closely as some of the dyes bleed in warmer solutions. Generally the temperature of solutions is 20–28°C.

Filtered deionised water is used, which means the minute particles in normal tap water such as iron or chlorine have been removed, preventing them being redeposited on the surface of the textile and causing degradation or iron staining. This type of water is also more chemically attractive to dirt particles, which are therefore pulled off the fibres into the water.

In the case of the illustrated 18th-century Indian Textile from the Coramandel Coast – composed of cotton with stable natural dyes of indigo and madder fixed with alum and iron based mordants – there were several large areas of brown liquid stains, particulate dirt and yellow discolouration. It was felt that the cloth would benefit greatly from washing and it was strong enough to fully immerse.

After several of the worst areas of staining had been spot treated with aqueous solutions the textile was placed into warm deionised water and soap solution, left to soak, and gently agitated to remove the general yellow cellulose degradation and the dirt stains. After 10 minutes the cloth was lifted onto towels then transferred into a warm rinse of deionised water. This was followed by two more rinses and then it was transferred by towels to a table to align the weave and flatten any creases or folds, eliminating the need for ironing. Once the weave was aligned, the excess water blotted off, and the last remnants of dirt drawn into the blotting paper, the textile was left to air dry overnight. The appearance of the textile was greatly improved. The blues and reds were more intense and the white areas were cleaner and brighter. The cotton fibres felt more supple and stronger in areas that had been weak before. The textile was then rolled up to await the restoration of the damages and holes.

When a textile cannot be immersed blotters and towels are placed underneath the textile on a table and the solutions are applied with spray or squeeze bottles. The liquids solublise the dirt and it is absorbed by the blotters. Again, any soap residue is rinsed out with several applications of deionised water and the blotters are changed in between each application of liquid. This is a more time consuming procedure and can often take two or three people a couple of days to complete.

Washing 500-year-old textiles can be a daunting and often stressful task but it is extremely rewarding to restore their strength and some of their former beauty.

Micheline Ford

First published in artonview 32 summer 2002-2003