Video footage of a freshman-to-be at Beijing University of Chemical Technology using the admission letter to cut a watermelon has astonished many netizens and aroused their curiosity as it looks just like a typical admission letter.

The secret of the sharpness of BUCT's admission letters lies in the material. This year, the university uses a new type of carbon fiber composite material to make its admission letters. This material was independently developed by the advanced composite materials research center of BUCT's College of Materials Science and Engineering. When viewed from different angles in the sunlight, the 0.2-millimeter-thick admission letters can change colors.

Dubbed "black gold," carbon fiber features lightweight, high specific strength, high stiffness and resistance to high temperatures and erosion. These exceptional properties make it widely used for major national projects, such as carrier rockets, large aircraft and large vessels.

"The carbon fiber-made admission letter not only showcases our university's exceptional abilities in the field of carbon fiber composite material but also marks the transformation of China's homegrown carbon fiber composite material from high-end industrial use to daily application," said Yang Xiaoping, a professor at BUCT's College of Materials Science and Engineering.