What is the study seal in the calligraphy seal?

You mean Zhai Haozhang, right? The house number stamp originated from the imperial seal of Li Biduan's bedroom in Tang Dynasty. After the Song and Yuan Dynasties, this trend became more and more popular, and almost everyone in calligraphers had the seal of fasting. Wen Zhiming, a calligrapher in the Ming Dynasty, said, "Many of my bookstores are printed." Zhai Hao is usually called Zhai, Tang, Shi, Lou, Ge, Guan, Xuan, An and so on. , such as Zhai, Tang, Shi, Lou, Ting, Lai Qin Ting, Yu Shang Xuan, An Le Tian and so on.