What are the factories that print stamps in New China?

After the founding of New China, there are many stamp printing plants, mainly including Shanghai Commercial Press, Shanghai No.1 Printing Plant, Dadong Bookstore Shanghai Printing Plant, Beijing China People Printing Plant (Beijing People Printing Plant), Shanghai Daye Printing Company, East China Taxation Bureau Printing Plant, Beijing People Printing Plant, China Hyundai Printing Company, Beijing Stamp Factory, East China Post Nanjing Printing Plant, Shenyang Post and Telecommunications Printing Plant and Henan Post and Telecommunications Printing Plant.