Initial survey responses, and personal experience over the past couple of decades, suggest a number of related issues: difficulty in establishing a reliable distribution source for paper in China, concerns over paper quality, and variations in conservation technique between China and the West. Chinese papers have been discussed in some detail in other issues of Hand Papermaking and in other readily available publications. I will focus here briefly on those papers used primarily in the conservation of rare books. Bast: Chinese bast-fiber papers are ordinarily made from several types of mulberry and are similar to Japanese kozo papers. Unlike Japanese bast-fiber papers, which tend to be 100 percent of a single type of fiber, such as kozo, mitsumata, or gampi, Chinese bast papers often contain mixed fiber types. The best Chinese bast papers for conservation have a high percentage of long bast fibers, are thin and flexible, and have a smooth surface. These are difficult to find commercially. grass : This category includes bamboo, rice straw, and other indigenous grasses. Bamboo yields a smooth-surfaced paper that is flexible when made but, depending on how the paper is produced, may decrease in flexibility with age. It was often used to print commercial editions of books and today is used for ephemeral functions, such as calligraphy practice and spirit papers. Bamboo paper is naturally yellowish in color, but white bamboo paper can be found, too, which has likely undergone chemical bleaching. Grass fibers are often mixed with longer fibers to adjust the properties of the paper, particularly how ink flows from brush to paper and how it is absorbed. Xuan : This is a mixed-fiber paper. True xuan paper is a combination of the inner bark (bast fiber) of the blue sandalwood tree (Pteroceltis tatarinowii) native to Central China and dryland rice straw. There are many different grades of xuan paper, depending on the ratio of bast fiber to straw and on other variations in the production process. Most commercially available xuan papers sold in the United States are used for calligraphy and are too thick and too rough for repairing old Chinese books using methods familiar to Western conservators. Xuan papers are smooth and white, have shorter fibers than many Japanese papers, but are long lasting and exhibit good wet strength during handling for lining or repairs. Almost all types of repair for old Chinese books can be done with the appropriate grades of xuan paper. At the 2014 annual meeting of the American Institute for Conservation, held in San Francisco, vendors offered a range of Japanese and Korean papers; two vendors displayed exclusively Japanese stock. In addition to greater access to paper products from Japan and Korea, significantly more formal opportunities have been established for conservators to travel to Japan in order to learn repair techniques. There are, of course, travelers to China who have published articles and books on their experiences—Nancy Norton Tomasko and Elaine and Donna Koretsky are good examples. And Megumi Mizumura continues to lead papermaking study tours through China. Despite the work of these scholars, an air of mystery remains around Chinese papers. Compared to Japanese and Korean stock, Chinese conservation papers are relatively difficult to find in the United States. Stationery shops in Chinatowns and chain art supply stores do carry rolls and bolts of usually anonymous Chinese papers, but the primary market for these is focused on painting and calligraphy. It is also possible to buy Chinese papers online, but it is difficult from abroad to verify the exact fiber content and properties of the paper being purchased—both of which are vital to the conservation process. Historically, Chinese binders and repairers purchased papers directly from individual papermakers. As detailed by Tomasko in a previous issue of Hand Papermaking, it is not uncommon for shops in one part of China to have exclusive deals with papermakers from a different region.3 In 2007 the National Center for Preservation & Conservation of Ancient Books was established at the National Library of China in Beijing, and modern conservation laboratories sprang up across China, causing a shift in the way many of the labs acquire papers. Conservators in national labs now report that while they still sometimes purchase directly from the paper producers, there is a growing trend for the National Center to acquire and distribute papers to the individual laboratories. Many conservation facilities in China buy up stock as quickly as it is produced, and then hold on to the papers for decades. It is not uncommon for conservators to let paper rest for at least ten years, as the aged material is said to be easier to use for conservation purposes. Further complicating the distribution of xuan paper is the recent phenomenon of paper auctions and the buying and selling of bolts of xuan paper as collectible items.4 Man Luen Choon, a supplier of xuan paper in Hong Kong, boasts on their website that they stock dozens of varieties of both new and aged papers; the aged papers can be purchased according to the year of production, similar to vintage wines.5 Likewise, the Red Star Paper Company in Anhui produces luxury lines of xuan paper sold in special gift boxes, with names such as Vintage Series, or as commemorative gifts for special events. The description of the "Qianlong \[Emperor\] Tribute Xuan Paper" series claims that the paper is made with the best traditional recipes that meet Qianlong-era standards, and that production is limited to 2,000 bolts.6 Xuan papers have been analyzed extensively. The literature holds data on pH, fiber length, tensile and tear strength, and photostability. 7 Traditional Chinese papers have proven to be alkaline Paper repair, applying thin wheat starch paste around the area of damage. Photos by Nancy Norton Tomasko. Placing repair tissue on top of pasted area. and long lasting. Certain modern Chinese handmade papers maintain that quality, but many more do not, making it difficult to identify which papers meet international conservation standards. Some papermakers are now adding wood pulp and repulped paper off-cuts of unknown fibers to the vats, using chemical bleaching methods, and applying alum as part of the sizing procedure for some treated papers. In a paper shop in Hong Kong, I recently counted more than 75 varieties of paper that claim to be xuan or imitation xuan paper. With such a wide range of products, it is nearly impossible to rely on the chemical and fiber analysis done by a single researcher. After xuan papermaking was inscribed on the UNESCO list of Intangible Cultural Heritage of Humanity in 2009, demand for the paper increased dramatically, and it is unclear what quality controls are in place or enforced. Western conservators have expressed interest in using Chinese papers for the treatment of rare books and other paper-based materials from China, but they are also insisting on more comprehensive testing and transparency in the manufacturing process. Throughout the Ming (1368–1644 ce) and Qing (1644–1911 ce) dynasties, thread-bound books were the predominant style of binding in China. Though many of these bindings are considered to be rare books,8 it is relatively easy to find and even handle examples. A quick search of the Council of East Asian Libraries website reveals that there are 48 institutional member libraries in North America alone. The International Dunhuang Project website offers nicely illustrated examples of various Chinese book formats and an article in the East Asian Library Journal provides visual examples.9 The majority of thread-bound books in collections today are printed from wood blocks. Each printing block was carved with a two-page spread for each sheet of paper. The block is printed only on one side of a relatively thin paper.10 The printed sheet is folded at the center along a printed guide that runs vertically between the two halves of the page, with the blank side to the inside of the fold. The fold becomes the fore edge of the text block. Folded sheets are then stacked and held together with twisted slips of paper inserted through holes punched along the unfolded edge. On standard bindings, colored paper covers are attached by stab sewing with thread through four additional holes. The beauty of the thread-bound book is that the inner paper twist holds the leaves of the text block securely together, and the outer cover and thread can be easily replaced if worn. Replacing worn-out book covers has been common practice by restorers in China for centuries. Other types of repairs, such as mending tears or holes in the text block, were done so as to hide the repair as much as possible, resulting in a book that appears almost brandnew. As David Helliwell points out in the introduction to his translation of a manual of Chinese traditional book restoration techniques, there has been a change in attitude toward conservation work: "certain procedures such as disguising repairs so that they are indistinguishable from the original and retracing missing portions of text have now been discontinued in favor of the more modern approach to conservation, which holds that any repair should be both visible and reversible."11 Coinciding with a marked increase in global exchanges and scientific research in the field, Chinese conservators have begun to employ more preventive conservation methods; however, the traditional desire remains to repair and restore to the fullest degree possible. In certain cases, papers are reproduced to match stock produced several centuries earlier. It is also common practice to remove blank endsheets (or other unprinted parts of old books) that will not be kept when a book is rebound, and retain these papers as repair stock, either for the book from which they were removed or for other old books. In addition to differing philosophical approaches to conservation, Chinese- and Western-trained conservators use different techniques for repairing books. For example, when repairing a book with insect holes, Western conservators are more likely to leave the sewing intact and mend the damaged paper in situ. Often wheat starch paste or another adhesive is applied to a thin Japanese tissue, such as tengujo, which is pre-cut or torn in the approximate shape of the hole, then applied to the damaged area. Another stabilizing repair, especially common in labs that prepare large quantities of books for digitization, is to apply smaller bridge mends to hold loose parts together. Chinese book conservators more often remove the sewing, open the folded sheets and repair holes from the back. A watery paste is applied with a brush onto the page in the area directly around the damage. A roughly cut repair paper is pressed onto the freshly pasted area, and the parts of the repair paper that do not adhere to the paste are then torn away. Chinese bast and xuan papers, both with some short grass fiber content, easily tear away from the shape of the repair but still provide enough strength to make a suitable repair. Such repairs do not overwhelm the original paper, which can be quite thin and fragile. Many Japanese- made papers have fibers that are too long to easily perform this type of repair and are of a quality entirely different from that of the original text paper, especially with regard to how they stretch and shrink when pasted out and dried during treatment. The structure of Chinese papers is perfectly suited to traditional Chinese repair methods, though Japanese (and some Korean) papers have been shown to work well for repairing Chinese books in Western conservation labs that are focused on minimally invasive repairs. In recent years exchanges and sharing of resources have increased between conservators in China and the West. I remain hopeful that the profession will continue moving towards a reliable source of handmade Chinese papers that are produced with high-quality raw materials and processes that result in long-lasting papers, sympathetic to the original objects and consistent with the standards of permanence required by international conservation professionals. ___________ notes 1. Several Asian painting conservation studios in the United States do make use of Chinese papers for conservation of scrolls. Some institutions make it a practice to hire conservators from China and to purchase directly from Chinese papermakers. 2. Fei Wen Tsai and Dianne van der Reyden, "Technology, Treatment, and Care of a Chinese Wood Block Print," The Paper Conservator (21), 1997, 48–62. The conservators chose to complete the structural repairs with Japanese-made tengujo paper, which is similar to some Chinese bast papers, but more readily available. They fill areas of loss on the surface of the print with toned Chinese xuan paper. 3. Nancy Norton Tomasko, "Chinese Handmade Paper—A Richly Varied Thing," Hand Papermaking, vol. 19, no. 1 (Summer 2004): 30. 4. Financial news article (in Chinese) about the trading and high cost of xuan papers. http://finance.sina.com/bg/investment/sinacn/20130406/1643738363.html (accessed June 8, 2014). 5. Man Luen Choon website, http://www.manluenchoon.com/paper.html (accessed June 8, 2014). 6. Red Star Paper Company website, http://www.hongxingxuanpaper.com.cn (accessed June 8, 2014). 7. Hilary Mullock, "Xuan Paper," The Paper Conservator vol. 19 (1995): 23–30. Analysis of xuan paper and description of the papermaking process. Also see Gang Chen, Kyoko Saito Katsumata & Masamitsu Inaba, "Traditional Chinese Papers, Their Properties and Permanence," Restaurator: International Journal for the Preservation of Library and Archival Material vol. 24 (2003): 135–144. The authors tested various paper samples from Jing County in Anhui. The xuan papers were alkaline (pH reading of 8.1–8.2), but had low physical strength. Moreover, after sizing, tensile and fold endurance increased while tear strength decreased, but the samples did not age well. The authors note that sun bleaching in some cases has given way to bleaching with sodium hypochlorite, and papermaking production methods vary. Surprisingly the samples with paper mulberry fiber deteriorated more quickly than papers with other fibers that they had assumed would be less permanent. One of their conclusions is that "the production method is as important as the raw materials." For more, see Ying Tang & Gerald J. Smith, "Fluorescence and Photodegradation of Xuan Paper: The Photostability of Traditional Chinese Handmade Paper," Journal of Cultural Heritage vol. 14 (2013): 464–470. 8. In a number of institutions, Chinese rare books are classified as those produced pre-1796, which corresponds with the end of the Qianlong era. 9. David Helliwell, "The Repair and Binding of Old Chinese Books," The East Asian Library Journal vol. 8, no. 1 (Spring 1998): 27–149. For examples of Chinese book formats, see International Dunhuang Project website, http://idp. bl.uk/education/bookbinding/bookbinding.a4d (accessed June 8, 2014). 10. Nancy Norton Tomasko, e-mail correspondence with the author, June 21, 2014. "…thinness of the paper does make show through a problem for printing on both sides of Chinese papers, but, too, printing techniques and binding styles make it terribly complicated to print on both sides of the sheets of paper. ..the thinness makes it possible for very large texts to be printed and bound into fascicles that are of a manageable thickness that retain flexibility. Thickness of the paper, printing techniques, binding formats, all have evolved in ways that are amazingly suitable for making a portable format for Chinese (\[as well as\] Korean \[and\] Japanese) texts. And, I might add, remarkably suited for conservation." For more detailed information on the thinness of paper and xylographic technique, see J.S. Edgren, "The Book Beyond the West: China," in Simon Eliot and Jonathon Rose, eds., A Companion to the History of the Book (Wiley-Blackwell, 2007), 100. 11. Helliwell, 30.
