Joppert's doctoral thesis was on the the grass script (caoshu) calligraphy of Huai Su. He described the evolution from seal script (zhuanshu), with his favorite development being the invention of bafen script (bafenshu), which was used for a famous rendering of the classics in stone under the emperor Xiping of the Han dynasty.
他的博士論文主題是以狂草傳世的懷素，其中以中國書法的演變為經，尤重篆書的變化，而他最愛的是漢喜平石經碑的八分書，便由篆書演變而來，所謂「八分取二分」之意。