Beijing University of Chemical Technology (BUCT) has introduced a unique admission letter made from a high-tech carbon fiber composite, just 0.2 millimeters thick yet sharp enough to cut fruit. This innovative material, known as "black gold," is typically used in rockets and aircraft but has been adapted for daily use, demonstrating BUCT's expertise in advanced materials. Other universities in China have also embraced creativity in their admission letters, using materials like bamboo and film slate designs.