Zhu Wen's raised words are called positive engraving, and the raised words are called negative engraving. However, after being engraved on paper, the white man was called Yang Wen, while the red man was called Yin Wen. Why? To know why, we must start from the pre-Qin period.
The seal began in ancient times. It was spread all over the Shang and Zhou Dynasties. The Qin and Han dynasties were in full swing. Today, there is inkpad coloring, which is made of paper and silk. In ancient times (Qin and Han dynasties), there was no paper. Where is the inkpad? The answer lies in the inkpad. Ancient people wrote on bamboo slips and tied them with ropes. They sealed it with clay and sealed it with copper seal for encryption. For example, the western mud sealing method is called mud sealing.
Bai Mo is carved in the mud, and the words on the mud are raised, so it is called Zheng. When carving Zhu Wen, the words on the mud are concave, so it is called negative. Today, the seal is engraved on paper and silk, and there is no difference between concave and convex. Therefore, Zhu is used to avoid confusion between yin and yang prints.