Changzhou micro-carving, a traditional art project in the second batch of representative projects of Changzhou's municipal intangible cultural heritage. Ivory shallow carving, also known as ivory line carving, flat carving, or ivory carving for short, is an important part of traditional ivory carving technology and a kind of literati carving combined with calligraphy and painting. It uses metal flat knives and hook knives as tools to make deep and shallow negative lines on the surface of ivory utensils and scrape them, and then uses brushes, ink, and pigments to fill the concave parts to form a picture. Changzhou ivory shallow carving first appeared in the Qing Dynasty. At that time, some green bamboo carving artists were engaged in ivory shallow carving and its products for a living. Zhang Jiru was a representative figure among them. In the late Qing Dynasty, Ma Zhihong (Zi Xiaoshan), a Changzhou native, inherited his ancestral foundation and successively established 8 ivory shops in Changzhou and other parts of the country, with the business name "Tianxiecheng". During this period, he hired and trained a large number of Changzhou ivory carving technicians, among whom Qin Xueni, Min Yaxing, and Wang Qingyuan were three generations of inheritance, all of whom were famous ivory carving masters and were well-known for a time. The art of shallow ivory carving in Changzhou has flourished since then, and spread to Changzhou and Wujin. In the middle of the last century, the distribution center of China's shallow ivory carving art slowly shifted from Shanghai and Jiangsu to Changwu, and together with Beijing's vertical carving and Guangdong's hollow carving, it became the three major schools of ivory carving today. The unique artistic characteristics of Changzhou's shallow ivory carving are the integration of the humanities of the Jiangnan region and the expression of calligraphy and painting art. The works are mainly based on humanities and history, landscapes, flowers and birds, and famous calligraphy and painting, accompanied by poems and inscriptions. The carriers of ivory carving are mostly ivory pen holders, book weights, seals, pendants, snuff bottles, table screens and other stationery treasures. In the early days, the ivory carving style focused on expressing the context of the work with line carving, and the air was ancient and elegant. Later, it gradually evolved. The artists made full use of the delicate texture of ivory, paid attention to the combination of points, lines and surfaces, and multi-level carving. The technique was skillful but not sweet, simple but not thin, scratched and carved, and partial to the artistic conception of ink, injecting cultural characteristics and caring about the aesthetics of the times. Inherited to the present day, original fine works have continuously emerged in the past few decades, and it is unique in the field of ivory carving in China. It is a traditional arts and crafts that carries traditional culture and embodies the characteristics of Jiangnan. Compared with the essence of ivory carving in Beijing and Guangzhou, which lies in "carving", the essence of Changzhou's ivory shallow carving lies in "carving". In the 1970s and 1980s, Changzhou's ivory shallow carving works were presented as state gifts to international dignitaries, and also became the main industry for export exchange. Since 1980, Changzhou's ivory shallow carving has won more than 150 provincial and national professional awards, and some fine works have been collected by many arts and crafts museums. On December 31, 2017, my country's legal ivory processing trade was stopped, and Changzhou's ivory shallow carving encountered a huge crisis of no raw materials for carving, and the inheritance of skills was once facing a desperate situation. Ivory carving artists responded to reality and looked for other carving materials as substitutes. Among them, mammoth ivory has become the most suitable substitute material at present. The skills of Changzhou's ivory shallow carving have also been passed on mainly through mammoth ivory.