1. Economic reasons: Silk and porcelain were valuable commodities that brought in a lot of revenue for China. By keeping the production methods a secret, the Chinese could maintain a monopoly on these products and prevent other countries from competing with them.
3. Cultural reasons: Silk and porcelain were also imbued with cultural significance in China. They were seen as symbols of Chinese culture and tradition, and the Chinese were reluctant to share them with outsiders. Additionally, the Chinese believed that the techniques for making silk and porcelain were sacred and should not be shared with those who were not part of their culture.