Paint Analysis of the Polychrome Paintings on the Corridor and Exterior of STUDIO OF SELF-RESTRAINT

The conservation project of Studio of Self Restraint started at the beginning of 2016. The Palace Museum and State Administration of Cultural Heritage (SACH) held a short training workshop based on this project, together with the CRAFT. We conducted the investigation, microscopic analysis, and research on the color paintings of the exterior and corridor of Studio of Self-Restraint, for the future conservation work. Supervised by Dr. Susan Buck, Private Paint Analyst, and LI Yue, Architectural conservator from Department of Ancient Architecture, the Palace Museum. Other members include participants from the museums and institutions all over China.

The traditional decorative paintings of ancient Chinese buildings include polychrome paintings on the upper structure (beams, purlins, Dou-Gong etc.), and oil paintings on the lower structure (columns, bars etc.) Susan had already analyzed the oil paintings on the lower structure. Our investigation and analysis mainly focus on the polychrome paintings on the upper structure.

Field Investigation

Measurement, Drawings and Photogrametry for Documentation

Examination (Collaborative teamwork)

Taking Samples of Brackets for Further Study (Collaborative teamwork)

Condition Survey (Collaborative teamwork)

Brief Summary

Through investigation, we discovered there are three generations of polychrome paintings campaigns on the buildings at least.

The most recent and majority of paintings on the studio are from 1950s’ and 1980s’ renovations, with thin and modern paints layers. (pink part in the plan)

An earlier generation, possibly painted in late Qing Dynasty, located in most of the upper structure of the corridor, and inner exterior of the studio. (green part in the plan)

The earliest generation is found in the corner of the corridor, higher structure and heavily degraded, which is likely to be the original campaign. (orange part in the plan)

Art History Research on the Style of the Polychrome Paintings on the Architecture

In order to understand the history of the polychrome painting in depth, verify our findings, and make sound basis for microscopic analysis, research was conducted on the style of the paintings on the architecture from art historical perspective. Supervised by Cao Zhenwei, specialist of Polychrome Paintings on the Chinese ancient architecture, the Palace Museum.

The style of the color paintings in Studio of Self Restraint is Sushi, widely used in the royal garden. The most significant characteristic is the use of gold. For the main building, large amount of gold was used in the outlines and main figures. The corridor was the secondary buildings, so that gold was used only in the important parts of the main figures.

Three stylistic characteristics of the polychome paintings, which were marked green above, indicate the majority of the existent paintings are from mid-Qing Dynasty, approximately Qianlong Period.

1. For the ending section of the painting on beam or purlin, known as Qiazi, mid-Qing Dynasty style was likely to use the straight lines with full of gold, or the curves with gold outline. While in the late Qing Dynasty, Qiazi were presented by both straight and curves with full of gold.

2. For the far end of the painting, known as Gutou, next to Qiazi, it was likely to be painted only white inside the gold line in mid-Qing Dynasty. While in the late Qing Dynasty, it was painted with another color stripe of light blue or green to make the fading effect.

3. For the glass-dragon figure, the mid-Qing Dynasty style had more changes in width and details. While the late Qing Dynasty style was uniform with no changes and details.

Microscopic Analysis

In order to collect more information for future conservation/preservation, we conducted microscopy analysis for materials and techniques, structure of layers, painting campaigns and connection with the oil paintings.

We took samples from different parts, covering the recognized periods and different colors.

Hypotheses And Conclusions

For the main building and some parts of the corridor, there is no enough evidence to prove it has been repainted several times. Probably because the earlier paintings were removed. The later repainting works have simpler cross-sections, most of them have only one layer, which is much different from the earlier generations. The later repainting works, especially after 1949, compared with both the studio and corridor, used modern pigment, whose layer is thinner than the earlier, and the ground layer has stronger fluorescence indication application of synthetic resin or adhesives.

The earliest color paintings we thought have been repainted later on, maybe a few years later from the earliest ones, in the same period, and made a new ground layer upon them. Comparing with the sample 2 that Susan took from the window frame, we’d like to consider the earliest paintings as the original works.

The later repainting work of the color paintings and oil paintings which are on the larger components like columns, removed the earlier works, but on the brackets and their frames, we can find a new ground layer upon the earlier layers.

The color configuration of the column, bench, window frames and brackets has changed a few times. The cross section helped us to know more about it.

The frame of the brackets was blue original, and have no change until recent years to be red. The original brackets were painted all red, then repainted to be blue for twice, then changed to red and later green in recent years. The window frames were red original, then repainted to be green and finally changed to red in recent years. The rafters may be green all the time.

We clarified the relationship between different generations of paintings.

The color paintings have been painted 4 times: the earliest original ones, then a repainting work likely only for maintenance a short time later on. And a complete renovation probably in Qing Dynasty, Guangxu period, which are mainly what we saw today(the green parts above). The recent repainting work in 1980s.

The oil paintings have been painted 4 or 5 times as the cross section shows.No solid evidence for the oil paintings of the columns and other bigger components’ original color. It might be referred to the brackets and so on.Color paintings might not be repainted in the same time, with the same techniques as the oil paintings.

Pigment Identification

The earlier blue pigment are mainly azurite, an expensive natural mineral pigment.One of the blue pigments we found which we thought were the earliest color paintings is smalt. This with the natural azurite may indicate the period of the color painting to Qianlong period.The green pigments we sorted out are malachite. These material were in common use in paintings on architecture, Qianlong Period.

Comments and Thoughts

Decorative coatings play an important role in traditional ancient architecture. The decorative coatings, including polychrome paintings and the oil paintings, in Studio of Self-Restraint are precious and typical examples which represent royal aesthetic preferences and artistic standard of ancient craftsmen during that period. They are of high value in history, culture, science, aesthetics and so on. Unfortunately they were not well preserved over years.

Our conservation research work lasts for only two weeks, endeavored to understand the problems, and to find the solutions.

Documentation, scientific analysis, treatments proposal and preventive conservation will be carried out within the conservation project.