C569 He Saw the Sheepskin Book Again

The Yin Condor, also known as the Heavy Condor, is a sculpting technique of indentation on the surface of the carving material, causing the characters or patterns to concave at the edges of the grooves and lower than the surface of the material, allowing the lines to have an upward, downward, and downward effect.

Although Zhang Zhiyan had already chosen the bookmark