The "High Three-Line Coffee Set" was designed by Yu Yanzhong, a professor at the Central Academy of Arts and Crafts. This set includes eleven pieces in total: a coffee pot, saucers, cups, a sugar bowl, and a creamer. The base of the pot bears the mark "Mansheng Pottery," and it is a masterpiece created by Gu Jingzhou as a sample for the Zisha Pottery Factory. The "High Three-Line Coffee Set" features a deep purple clay color, clean and lustrous. The form is simple and elegant, with a round, straight body. Three circular lines decorate the shoulder, waist, and base, dividing the pot body into two sections—smaller above and larger below. It has a curved handle and a ring foot, with a graceful spout emerging from above the waist line, refined and elegant. The inset lid is slightly domed, full and dignified. Gu Jingzhou devoted tremendous effort to the production and innovation of Zisha pottery. In the 1950s and 1960s, Gu Jingzhou actively advocated for the development of new products, organizing and participating in the research, development, and production of Zisha colored clays and glazes. This "High Three-Line Coffee Set" with its interior glaze was born in this context.