The study object was the mother-of-pearl floor mirror displayed at Daejojeon Hall of Changdeokgung Palace. A floor mirror refers to a big mirror that can reflect the whole body. The size of the mirror was 2095 × 905 mm and overall, the color was dark brown. Swallow-tailored weaving was applied to the mirror. The top ornament unit, mirror frame and bottom support surface were decorated with motherof- pearl. For mother-of-pearl decoration, the wood was carved in shape of mother-of-pearl for attachment. And a thin engraved line was made on the surface of the surface of mother-of-pearl to express details(Figure 1). Total length of the mirror was 330 mm and wooden frame encompasses the mirror. Wooden material and paper were inserted as a shock absorber between the mirror and the frame. In addition, the edge of the wooden material was decorated with metal line. The top of the bottom support was decorated with vine pattern using open work method and marble ornament in the shape of a pot in the middle. The front and rear side of the legs were carved to create paw of an animal and metal wheels were attached for mobility. These were the features of typical Chinese furniture and in fact there was a record that the furniture installed in Daejojeon Hall was imported from China(Kee, 2014).

Permanent exhibition is organized to make it possible to observe inside of Daejojeon Hall of Changdeokgung Palace by opening the door in the front side. Therefore, relics exhibited in Daejojeon Hall have been easily influenced by environmental changes. The mother-of-pearl floor mirror, which was displayed in such an unstable environment, had many pollutants accumulated such as dust from outside. And wooden material was deformed as mirror was hung for a long time bending the pillar(Figure 1a). In addition, overall surface was covered with yellow transparent material. The transparent material was assumed to be changed due to aging and stuck on the surface of motherof- pearl. Some of the mother-of-pearl ornaments were eliminated to the extent that the original surface of the wood was exposed and some part did not have a thin engraved line making it possible to assume that repair work was conducted later. The body and 4 connection materials that fix legs existed but the right side materials were lost in the front side and loosened. This made the whole structure be swayed, resulting in unstable structure. In addition, some wheels attached to legs were loosened to the extent that their function was lost.

The relic was in very unstable condition structurally so the whole parts were disassembled for observation. The disassembly results showed that the structure was divided into body, mirror, and legs.

The body was composed of the pillar that fixed the mirror and square shape support. The mirror was made as all-in-one type. At the top, flower shape ornament plate was inserted. The pillar was made to be a circular shape and only jonit parts had square pillar. The mirror frame and pillar were fixed using screws that made of metal. The wooden material was processed to be a circle shape to decorate head of the mirror.

The wooden material for mirror frame was made using mitre joint and mother-of-pearl and metal line were inserted on the surface for decoration. Mirror was connected to the inside of the frame and wooden materials in the shape of a thin rope was put(Figure 2a) and paper was applied(Figure 2b). Then wooden cover was inserted(Figure 2c). The wooden material in rope shape seemed to play the role of shock absorbing material to protect the mirror. The back cover has the basic frame in the shape of 日 and rectangular plate was attached within the frame. The traditional paper was attached for joint area for fixation and some area on the traditional paper was ripped. The cover had two fixing devices that connects each face with the mirror frame. The device on the left bottom was lost. The fixing device at the top was fixed and others can be attached and detached. The orange coating material was applied on the backside of the mirror and some part of edges had peeled off coating material.

There were two legs and they were made not to be separated by inserting sub materials in the same width and length of the body support on the front and back(Figure 3). At the base of the legs was attached with metal wheels. The wheels were made to rotate in every direction(Figure 4).

Overall dry cleaning and wet cleaning were conducted at the same time. Small tools such as an air blower and a brush were used to light foreign materials attached to the surface. Nacre cutting knife was used to remove yellow materials stuck on the wood surface physically for thick area and ethanol 50 wt.%(in water) was used for thin area. The cleaning for mother-of-pearl was done using nacre cutting knife and magnifier to remove only pollutants and second cleaning was conducted using distilled water. Ethanol 50 wt.%(in water) was used for cleaning marble decoration located at the center of body support(Figure 10).

Based on the results of wood identification, leg connection was made using Shorea spp.(lauan). The wood processing was conducted by Hyundae Buddhist Sculpture Center, a service team for Changdeokgung management office. The restored materials were finished with lacquer varnishing to be in harmony with the relic. Lacquer and refined lacquer were done for 2 times respectively conducting varnishing for 4 times in total for making similar color.

The treatment was done focusing on lost and damaged cover and exfoliated coating material on the glass. The coating material of mirror peeled off at the edge was bonded using Parloid B72 10 wt.%(in acetone). In addition, it was applied to the crack to prevent peeling. It was decided to replace the traditional paper which was attached to the inside of back cover as it was damaged significantly. The existing traditional paper was removed slowly after making it humid. After the removal, wheat starch glue was used for attaching mulberry paper(Figure 11). The materials lost from the mirror cover was made using bamboo and color was matched by using acrylic painting(Figure 12). The wood shock absorber and paper included in the mirror was aged. Therefore, they were removed and replaced by DuPont^® paper, which has high stability.

The wheels attached to the legs were weakened with deformation of metal for long term use. The original function of the wheels was lost. To solve this problem, the wheels were disassembled and reinforced. The lead strap was used for metal part to fix the loosened area after disassembly. Table 2

In the future, the floor mirror at the Daejojeon Hall, Changdeokgung will be exhibited outside. Therefore, surface treatment was conducted considering the impact of external environment. For surface treatment, Carnauba wax was used. Carnauba wax is a natural wax extracted from palm trees. Wax brush and fine-fiber cloth were used for thin application on the surface. After surface treatment, reassembly was done in the opposite order of disassembly. The restored materials were inserted.

Foreign materials stuck on the surface were all removed after conservation treatment. In particular, the unique color of mother-of-pearl was restored by removing pollutants stuck on the surface.

The function of wheels was restored with reinforcement as they were damaged due to long-term use and non-management. The lost materials were restored and assembled to make a structurally safe condition resulting in now swing.

The wood, which shock absorber in the mirror, was removed and DuPont^® paper was used as it can serve as a shock absorption material.