The paper used in the conservation treatment of paper artifacts is typically dyed using East Asian alder berries or acorn tops according to the methods prescribed in many ancient documents. Paper is dyed a natural brown and then cut into thin strips before being used in conservation treatment.
Dyeing refers to the extraction of coloring matter from various raw materials and dyeing fabrics or paper. The National Palace Museum of Korea houses a collection of many artifacts, such as royal garments, bundle wraps, poetry paper stock, and books, created based on the five cardinal colors (red, blue, yellow, black, white). Unfortunately, once-brilliant colors fade and discolor as time passes, and the materials used in the restoration of artifacts must be appropriate to the time period to appear natural.
Dyed hanji (traditional Korean paper made from mulberry trees) paper used in the restoration of paper-based artifacts are often brownish in tone, and thus, East Asians alder berries and acorn tops are often used to obtain such colors.
Dyeing methods using these materials are often described in ancient literature. Imwongyeongjeji (林園經濟志; lit. "Treatise on Forestry and Economy") includes the following passage that describes how a dye is obtained using the bark of an East Asian alder tree: "Cut old apricot wood into thin pieces and boil until the water is reduced by two-thirds. Dry the bark of an alder tree, and then it grind into powder and soak in water. Add 2 or 3 hops (1 hop = 180.39 ml) of powder and dye."The ancient Chinese text Geogapilyong (Jujiabiyong, 居家必用; lit. "Household Essentials") includes a record that states, "For ten units of silk: Add four units of finely-crushed shrubbery, one unit of finely-ground acorn, two units of alum, and green vitriol. The materials and dye method are the same as those for sohong."Sanlimgyeongje (山林經濟; lit. "Management of Rural Economy") states, "Yellow-brown is dyed by using water boiled with oak bark,"which confirms the use of acorns for dyeing purposes since ancient times.
To select dyed hanji paper suitable for artifact restoration, it's necessary to first prepare multiple shades of color by using a variety of dyeing methods.
To dye using alder berries, for example, the first dyeing solution is prepared by boiling 20 g of berries in 1,000 ml of distilled water for 1 hour. The process is repeated to obtain a second solution by boiling 40 g of berries, and a third solution is prepared by boiling 60 g of berries. Hanji paper is then soaked in each of the obtained solutions. Once soaked in dye, the paper is then rinsed in clean water and dried.
Dyeing work, in preparation for creating a restoration material that can satisfy aesthetics, stability, and differentiation from the original form, requires experience as well as multiple rounds of experiments. Of course, the ideal scenario would be having a precious artifact that's preserved with the passing of time without damage or deterioration.
This is unlikely, however, and an artifact that has already been damaged must be structurally supplemented to prevent further deterioration. Much consideration and selective processes are required so that a new supplementary material achieves the right balance with an artifact to begin a new and meaningful lifecycle.
NATIONAL PALACE MUSEUM OF KOREA