Study of bamboo and wooden slips

By CHEN WEI / 07-01-2021 / (Chinese Social Sciences Today)

FILE PHOTO: A detail from the written bamboo slips preserved in the Palace Museum 

The study of bamboo and wooden slips has a long history in China, as bamboo and wooden slips predated the wide use of paper as a writing material. By the Zhou Dynasty (c. 1046–256 BCE), bamboo and wooden slips were the primary medium for documents in China. After the Spring and Autumn Period (770–476 BCE), there were many records mentioning these wooden texts. Before paper was designated the official writing material in the late Eastern Jin Dynasty (317–420), bamboo and wooden slips had long been used for writing, coexisting with the other writing materials such as oracle bones, bronzeware, stone slabs, and silk. Bamboo and wooden slips used to be the most popular writing material, because they were easy to produce, and the raw materials were not difficult to obtain. 

The earliest discovery of ancient bamboo and wooden slips in our modern era occurred in the early 20th century. Afterward, many more wooden texts were discovered. So far, over 300,000 pieces of slips, containing more than three million Chinese characters, have been unearthed. These wooden slips mainly date from the Warring States Period (475–221 BCE) to the Wei, Jin, Southern and Northern Dynasties (420–589), among which the earliest surviving examples date to approximately 433 BCE or later. These early samples were excavated from the tomb of Marquis Yi of Zeng in Hubei Province. No wooden slips dated earlier than the Spring and Autumn Period have been found yet, perhaps because they were too fragile and ancient to survive to today. 
New stage of development
Near the end of the 20th century, the study of bamboo and wooden scrolls entered a new development stage and took on several new features.
Bamboo and wooden slips have been unearthed at an increasing speed, perhaps due to China’s growing infrastructure projects. For example, in 2010, more than 700 Chu slips (bamboo slip texts dating to the Warring States Period) were excavated from Huanzizhong Tomb in Jingmen, Hubei Province. In 2015, archaeologists found over 400 Chu slips from Xiajiatai Tomb No.106 in Jingzhou, Hubei Province, which included manuscripts of the chapter “Odes of Bei” from the oldest existing collection of Chinese poetry, Shijing (Book of Poetry), and the text “Marquis of Lu on Punishments” from the pre-Qin Confucian canon Shangshu (Book of Documents)
As for the Qin slips (scrolls dating to the Qin state before and after it unified China as a centralized power, 770–207 BCE), over 38,000 wooden slips were unearthed from the site of the ancient city Liye in Hunan Province in 2002. Among these, there are more than 17,000 slips on which writings survive to today. Most unearthed wooden texts were written from the Han Dynasty (206 BCE–220 CE) to the Jin Dynasty (266–420). In 2015, over 5,000 bamboo and wooden slips were discovered in the tomb of Liu He (?–59 BCE), a Western Han Dynasty Emperor who was deposed and later made Marquis of Haihun. These slip texts included some Confucian classics, such as Shijing, Chunqiu (Spring and Autumn Annals), The Analects, and Xiaojing (The Classic of Filial Piety). The abundant excavations of bamboo and wooden slips constantly fill in blanks on the chronological sequence of these special archives, providing more space and possibilities for the study of their history.
In the 21st century, special editions on bamboo and wooden slips have been published at an impressive rate, including separate editions such as Jiudian Chujian (Chu Slips from Jiudian, 2000) and Changsha Chujian (Chu Slips from Changsha, 2000), and multi-volume works such as the ten-volume Qinghua Daxue Cang Zhanguo Zhujian (Bamboo Slips of Warring States Period Preserved in Tsinghua University, first published in 2010).
The new stage of development also features emerging publications of collected papers on the study of wooden slip texts, in addition to academic websites. The annual journal Chutu Wenxian Yanjiu (Research for Unearthed Texts), published by the Chinese Academy of Cultural Heritage, is foundational to collections and research regarding unearthed texts. This journal began its publication in 1985. The non-periodical publication Jianbo Yanjiu (Research on Bamboo and Wooden Slips) began publishing in 1997, and is issued by the research center of bamboo and wooden slips under the Chinese Academy of Social Sciences. In the same year, the College of History and Culture at Northwest Normal University started to publish Jianduxue Yanjiu (Research on the Study of Bamboo and Wooden Slips). These works have made unique contributions, advancing the collation and research of bamboo slips.
Some specific websites dedicated to the study of bamboo and wooden scrolls have been publishing academic papers and study notes in a timely manner, and continuously updating their research. These websites include “” ( set up by renowned historian Pang Pu (1928–2015) in 2000, and websites from the Center of Bamboo Silk Manuscripts of Wuhan University (, the Research Center for Unearthed Literature and Archaic Chinese Characters of Fudan University (, and the Research and Conservation Center for Unearthed Texts of Tsinghua University (
Application of new technology
In the new stage of development, the whole process of handling unearthed slips, ranging from jiequ (the process of carefully removing soil or other residue adhering to slips), cleaning, decolorization, preservation, photographic documentation, to collation and publication, has been supported by new technology and new equipment. 
Bamboo scrolls unearthed in south China have been buried underground for many years, during which time they were eroded by various factors, such as microorganisms, acid, alkali, salt, and groundwater. After excavation, these slips often oxidized, turning dark brown due to sudden exposure to light and air. This makes writings on the slips difficult to identify. Decolorization uses chemicals to restore the original color of wooden slips. 
In 1953, archaeologists discovered wooden slips in Tomb No.25 at Yangtianhu in Hunan Province. Four years later, photos of the slips that had been decolorized using oxalic acid were published. This might be the earliest application of decolorization in China’s unearthed wooden texts. For a long time following this, decolorizing bamboo slips with oxalic acid was a mainstream approach. However, the acidity of oxalic acid could severely damage wooden slips. In the last two decades, experts in cultural relic protection developed more efficient approaches to decolorize wooden slips by using sodium hydrosulfite or a low concentration of hydrogen peroxide. The Jingzhou Cultural Relics Protection Center in Hubei Province succeeded in decolorizing the bamboo and wooden slips unearthed from Guodian tombs, Liye ancient city ruins, and Zoumalou at Hunan Province, with sodium hydrosulfite. 
Photography has been used to document bamboo slips since the early 20th century. In recent decades, the study of bamboo slips has benefited greatly from the rapid development of technology in conventional photography and the advancement of digital cameras and thermal imaging equipment. Infrared rays can “sense” ink stains which penetrate into bamboo slips. Therefore, thermal imaging equipment captures more information than conventional cameras do when the bamboo slips are stained, damaged, or when ink peels off the surface. 
Japanese scholars used infrared imaging technology to shoot wooden slips earlier than the Chinese did. In 1990, the Institute of History and Philology at Academia Sinica purchased a Canon infrared camera from Japan and took photos of the Juyan bamboo slips (Han Dynasty slips unearthed in northwest China). They published Supplement to Juyan Han Bamboo Slips in 1998. Fudan University developed infrared imaging equipment and used it to observe both the Longgang Qin slips and Yinwan Han slips in 1995 and 1996 respectively. In 1995, the Bei Shan Tang Foundation from Hong Kong donated a set of infrared imaging equipment to Hubei Provincial Museum. In recent years, many research institutions have purchased infrared scanners or infrared cameras. Infrared imaging technology is becoming an increasingly popular tool for obtaining information on bamboo and wooden slips.
In addition to advanced technology, the study of bamboo slips is financially supported by numerous funds. Thanks to a growing economy, projects which collate and publish bamboo slip texts are receiving financial support from various funds. Furthermore, the newly launched project, Inheritance and Development of Ancient Chinese Characters and Chinese Civilization, will create a more stable financial environment for the study of bamboo and wooden slips.
Problems to overcome
Some of the slips listed above only took a few years from being unearthed to their collation and publication, which is quite efficient. However, there are still some important slip texts which cannot be systematically collated and published, even though they have been unearthed for decades. As time passes, some data and records may be lost or even damaged, causing irreparable cultural loss.
Admittedly, pursuing high-quality analyses and records of slip texts should be the common goal of all text archivists. However, we should be aware that any batch of unearthed archives with rich content will begin a long-term discussion with analysis from many scholars, after the original materials are released to public. Only in this way can we reach a high level of text restoration and interpretation. The expectation to accomplish the whole task in one stroke is very unrealistic. Initial interpretations of slip texts may vary considerably in quality, due to interpreters’ different levels of knowledge and effort. It is almost impossible to reach the “final version” during the initial stage of interpreting the texts. Works should be regarded as “shanben” (a reliable version or classical edition), as long as they can provide detailed records of the excavation and sorting process, illustrations of texts that are as clear as possible, and roughly correct explanations and interpretations of the texts.   
Chen Wei is the director of the Center of Bamboo Silk Manuscripts at Wuhan University.