23 Conservation of Ancient Thai Books by Chiraporn Aranyanak A or a square-shaped piece of cloth. The fibres are then spread Ancient Thai books or Samut Thai are important out into flat, thin sheets. The water is allowed to drain away handwritten manuscripts in Thailand which have been in use and the mould is gently shaken from side to side to ensure for a very long period. A large numbr of ancient Thai books even formation of the sheet. The excess water is removed by produced in the Ayutthaya period (1350-1767 AD) are still rolling with a bamboo stick. The mould is then placed in in service. The major contents of Thai books are Buddhist the open air to dry and, when dry, the sheet of paper is scriptures, various sciences, historical records, political removed. leaders and their achievements, literary works, etc. A number of them are illustrated manuscripts while others are just texts. Illustrated manuscripts, are widely known as one of the Thai classical arts. The painting techniques are similar to those used in Thai mural paintings. The painting can either be on one side only or on both sides. MATERIALS AND TECHNIQUES Ancient Thai books are made of locally hand-made paper produced from plants of the Moraceae family. The paper produced from Siamese rough bush or toothbrush tree (Streblus asper Lour) is called khoi paper and the paper produced from paper mulberry (Broussonetia papyrifera Vent.) is called sa paper. The barks of these plants are removed from the stem and soaked in water for 3-4 days. They are then steamed for 48 hours and soaked in dilute lime solution for about 24 Fig. 1 White Thai books and black Thai books. hours. The wet fibres are pounded by hand until they reach a condition suitable for paper making, and they are then made into a dilute suspension in a large tank or vat. A portion of the suspension is dipped into a The paper is then sized with starch mixed with lime rectangular mould fitted at the bottom with a wire screen solution. The Thai book produced from this sized paper is called White Thai Book or Samut Thai Khao. Another type of Thai book called Black Thai Book or Samut Thai Dam The author is a Senior Scientist in the Conservation Section of the Bangkok is produced from the paper sized with starch mixed soot or National Museum, Department of Fine Arts, Thailand. charcoal powder (Fig. 1). It is a very strong and durable material. 24 characterized by uniformly high temperature and heavy rainfall distributed throughout the year. In Bangkok, day-time temperatures are usually around 30 C. The night temperature may be about 28-30°C in the warmer period and 18-22°C in the cooler period. Daily temperatures normally vary by not much more than 2-3 °C. Relative humidities inside a building are usually around 60-70% most part of the year. These climatic conditions (Figs. 3-5) affect the deterioration of ancient Thai books in many ways. Insects Insects play the most important role in the deterioration of ancient Thai books. A detailed survey of insects living on ancient Thai books revealed that termites often cause extensive and irreparable damage.1 The common species is Coptotermes havilandi (Holmgren). It is one of the subterranean termites belonging to the family After drying, the surface of the paper is smoothed or Rhinotermitidae. They enter buildings through cracks and burnished by rubbing it with a polished stone. Many pages crevices in the foundations. Climate conditions in Thailand of paper are joined with starch paste to make a long sheet are optimum or near optimum for termites throughout the of paper. This sheet of paper is then folded accordion- year. fashion into the desired size for the book. The folded sheets Several species of the family Anobiidae are among the can be between 30-60 cm long by 12-20cm wide. When most destructive insects in libraries, museums, archives, unfolded the pages can be more than 18 metres in length. temples and in private collections. The dominant species of Writing in beautiful calligraphic style is executed anobiid beetle is the bookworm beetle (Castrilus sp.) under the lines at regular intervals. Materials used for writing Infestation is frequently overlooked, especially in the early on Thai books are mainly soot, Chinese ink, a white pigment stages of the attack. The female adults lay eggs in holes or obtained from mother-of-pearl, red pigment from annatto crevices in the books. The young larvae, when they hatch, (Bixa orellana Linn), gold leaf, yellow pigments from are about 3mm long and they are creamy-white in colour. gamboge (Garcinia hanburyi Hook.f.) and orpiment. The body is soft, vermiform, cylindrical and curved. The Covers of ancient Thai books are mostly applied with thoracic segments are larger than those of the abdomen, lacquer and some have gilt decoration on the black lacquer giving a distended appearance. Their mouthparts are formed background. for chewing. The anobiid larvae dig long, round galleries that A small proportion of ancient Thai books are made usually work from the edges toward the centre of the book of textiles, for example, cotton and silk (Fig. 2). Writings are (Fig. 6). Both flight holes and tunnels are circular in section executed by means of embroidery. and about 1-1.5mm in diameter. In the past these ancient Thai books, wrapped in a Other important species belonging to this family are piece of cloth, were mostly kept in a temple scripture Stegobium sp. or drugstore beetles, and Lasioderma repository located in the middle of a pond to prevent insect surricorne (F.) or cigarette beetle. attack. In Thailand, cockroaches are very active all year round. They produce superficial erosion of irregular shape and also CAUSES OF DETERIORATION cause unsightly stains and unpleasant odours. The major The most common causes of deterioration of ancient species are Periplaneta americana (L.) or American Thai books are as follows. cockroach, Periplaneta brunnea Burmister or large brown cockroach, Neostylopyga rhombifolia (Stoll) or harlequin Humidity and Temperature cockroach, and Supella longipalpa (F.) or brown-banded Since Thailand is situated near the equator, the climate is cockroach. Eggs enclosed in egg-cases are laid in tiny cracks 25 Fig. 3 Variations of climatic conditions inside a building in Bangkok National Museum. Fig. 4 Temperatures compared for air-conditioned and non air-conditioned rooms. (Air-conditioning operates 9 a.m.- 4 p.m.) in the walls and in hidden places. Both nymph and adult are The nymphs and adults have the same appearance except for harmful stages of these insects. the lighter colour of the nymphs. They cause tiny surface Serious damage is also caused by silverfish and firebrat, holes with irregular shapes. The dominant species found in primitive insects of the order of Thysanura, family libraries and museums in Thailand are Liposcelis spp. Lepismatidae. They feed mostly on starchy, sugary and Fungi cellulose products. Therefore ancient Thai books are their Ancient Thai books are commonly damaged by fungi. favourite food. They are also very active all year round. The The production of mycelium as well as spores and other length of the life-cycle is 1 - 2 years. Three dominant species propagules causes a lot of undesirable situations, e.g. of silverfish and firebrat were identified: Lepisma saccharina distinctive odour, unsightly spotting, stubborn stains, (L.), Acrotelsa collaris (F.), Thermobia domestica (Pack). decrease in strength, decrease in flexibilily, etc. 2 Booklice are commonly found on ancient Thai Many fungal species have been identified. The books. They feed mainly on flour, glue, paper and fungi. dominant species are Trichoderma spp., Geotrichum spp., 26 Fig. 5 Relative humidity compared for air-conditioned and non air-conditioned rooms. (Air-conditioning operates 9 a.m. - 4 p.m.) Aspergillus niger, Aspergillus terreus, Aspergillus candidus, CONSERVATION TREATMENT Aspergillus flavus, Aspergillus fumigatus, Chaetomium Cleaning globosum, Helminthosporium spp., Cladosporium spp., Penicillium spp., Fusarium rosium, and Curvularia spp., The first step in the cleaning operation is dusting with The study revealed that more fungal species were found in a soft brush. Accretions or stains on those parts where the air-conditioned rooms than in those without air-condi- ink or paint is not soluble in water are usually removed by tioning. a swab of cotton wool moistened with water or a mixture Paper, starch and the binding medium of the paint are of water and ethanol (about 50 : 50). The proportion of all nutrient materials for fungi. The growths of certain fungi ethanol and water can be varied according to need. appear as black, brown, green, yellow and purple spots on Various organic solvents are also used for the removal the paper (Fig. 7). Some fungi produce pigments, pigmented of resistant stains. Some of the organic solvents that are mycelia, spores and some reproductive structures on the found useful are ethanol, methanol, xylene, toluene, acetone surface. and trichloro-ethane. Treatment against fungi Light In the case of an outbreak of fungus, the infected paper Most of the exposed ancient Thai books are, more or is firstly kept in a well-ventilated condition and is dried. The less, invisibly damaged by long exposure to light. Ultraviolet dried mould is removed with a brush and a cotton swab. and visible radiation bring about a number of changes in Fungal mycelia are cleaned off with ethanol. the physical and chemical properties of paper and textiles. The book is then fumigated with thvmol vapour in a Most of them are embrittled, weakened and discoloured. gas-tight chamber which is slightly warmed with a heating Paints, inks and other design materials have faded.