To some extent, the grease secreted by human daily metabolism can be viewed as a trace of life. When people come into inevitable contact with substances, especially skin-friendly materials in the surrounding environment, this physiological vestige of human metabolism will infiltrate and cover such items. This translucent substance will be weathered over time and gradually hardened, and eventually become a permanent token that tells stories of human activities and thus bear certain historical value. For instance, in Chinese culture, a jade collector would purposefully play with the jade by secretions produced in his hands to create a more warm and shiny protective film to cover it. More importantly, the transmission of human energy into the cherished unanimated objects is highly valued by the Chinese people because they embrace the faith “all things on earth have spirits.”
