When driving around Bangkok you’ll notice long stretches of ornamental plants; dense, hedge-like bushes cut into different decorative shapes. The straight twigs and leaves at the end of the branches might be shaped into spheres, and sometimes the entire plant has been sculpted into an animal form, elephants being especially popular. Often, a row of the dense plants will be planted next to a wall to create a parallel, vegetable fence.
This shrub, which lends itself so attractively to decorative cutting and shaping, is the khoi plant, or Siamese rough bush. It is widely used in Bangkok for ornamentation and is quite expensive when bought in the capital. But if you travel north and look at some of the older houses in small communities you’ll see hedges of a similar plant trimmed to form fences. They look neat and attractive, are inexpensive to plant and maintain and are always green. These plants are called chaa soi, and are a relative of the khoi plants in Bangkok.
Khoi works so well as an ornamental plant that it seems almost to have been created for this role, but its usefulness is not limited to just this one thing. Originally it was widespread in nature and grew on the edges of forests, in gardens and in the middle of fields. The plants were plentiful, lived for many years, and were very tough and hardy.
Back in the days when Thais still lived on houseboats or in woven nipa leaf houses illuminated at night by lanterns, they used toothbrushes made by pounding one end of a small, mature khoi twig until the fine fibres separated to create a brush. It served as a combination of toothbrush and toothpaste, and lasted a long time because of the durability of the tough khoi wood. Modern research has shown that the sap of the plant has medicinal qualities that help to maintain the health of the roots of the teeth. It is also effective in treating some stomach disorders.
As for the leaves, the bottoms are rough and abrasive, like sandpaper. In the past, when cooks prepared a dish using a fish that had no scales, especially an eel, with its unattractive slimy skin, they would tie it in place or hang it from a cord passed through the gills and tie it to a tree branch, then rub it vigorously with khoi leaves until all of the slime and skin were removed. The same technique was used with catfish and local scaleless species like the plaa sawai. The idea was to give the fish a more appetising appearance and remove the fishy smell. It is a shame that nowadays cooks are rarely able to do this, since most of the naturally growing khoi plants in forests and fields are gone.
Centuries ago, the khoi plant had another very important use because of the strength and durability of its fibres. The pulp was made into paper to make the volumes called “samut Thai”. It would be folder over itself to make thick sheets, and these were used to record religious texts, books on traditional Thai medicine, historical annals, and legal documents. These old samut Thai are remarkable. Besides being strong and durable, they are resistant to all insects (termites will eat the chests they are stored in, but not the volumes themselves).
In the modern era, Thailand’s national constitutions are also written as samut Thai. Although they are drafted and published using other formats and materials, a samut Thai version is also prepared for symbolic purposes.
Khoi paper was used in the past to make the masks used in traditional Thai khon dance drama. The heads of the giants and characters like Hanuman were formed from khoi paper laid on in many layers to make the masks. The material was very firm and strong so the masks held their shape unchanged over long use.
Since actors wearing the masks would sweat during performances, the paper would become wet, but then dry without any loss of shape, and it did not take on any odour from the perspiration. It is sad that khoi paper is no longer made, as there are no artisans to do it. The old neighbourhood that was the source of the paper, originally at Bang Pho in Bangkok, is gone, and there is no one left who knows how to do it.
In the past there was the canal called Khlong Kradaat (“Paper Canal”), which connected to the Chao Phraya River. It ran parallel to Sawai Suwan Road, which is now the city’s main locale for stores specialising in teak furniture and other wooden items and household decorations. It was a large, clean waterway, with water flowing in from the river. Many of the residents who lived on its banks made khoi paper for a living.
They would have to buy mature khoi wood in the provinces, obtaining it in quantity to store for long-term use. It would be cut into segments and soaked in water for days. When it was completely saturated it would be pounded with hard wooden mallets. The sound of pounding from so many households made a real racket. After the wood had been pounded it would be soaked and pounded again, several times, until it was reduced to fibres.
The final step was to spread the fibres out over a thin woven bamboo screen to form a thin sheet. This was done under water. When the sheet was complete, the screen was lifted out of the water and set in the sun to dry. Once dried, the fibres formed a sheet of paper that was ready to use.
No one has made any khoi paper for more than 40 years, and Khlong Kradaat has shrunk from a clean canal to a drainage ditch that carries polluted water from neighbourhood houses.
Khoi paper was once an important part of everyday Thai life, an essential material on which historical records and religious texts were written and which was indispensable for the performance of one of the country’s highest and most refined performing arts. It is regretful that the plant that yielded it is now appreciated only as a decorative shrub growing beside the road.
Natural beauty: Khoi plants are now trimmed into different ornamental shapes near roadways and buildings, while khon masks are traditionally made from khoi paper.
This source first appeared on Bangkok Post Lifestyle.