What are the famous producing areas in Four Treasures of the Study?

Four Treasures of the Study refers to the instruments and tools in the traditional culture of Han nationality in China, that is, pen, ink, paper and inkstone. But its most famous place of origin often changes. Roughly as follows: \x0d\ 1) "Four Treasures of the Study" in Southern Tang Dynasty refers to Zhuge Pen in Xuancheng, Anhui Province, Li Tinggui Ink in Huizhou, Anhui Province, Chengxin Tang Paper, and Weilong inkstone in Wuyuan (originally from Huizhou, Anhui Province, but now it belongs to Jiangxi Province). \x0d\2) Since the Song Dynasty, "Four Treasures of the Study" refers to Hubi (Huzhou, Zhejiang Province), Huimo (Huizhou, now Shexian County, Anhui Province), Xuanzhi (now Jingxian County, Anhui Province, which belonged to the Ningguo government in ancient times and produced paper under the name of government governing Xuancheng), Yan Tao (now Zhuoni, Gansu Province) and Duanyan (now Zhaoqing, Guangdong Province, which was called Duanyan in ancient times). \x0d\3) Xuancheng in southern Anhui is the only "hometown of Four Treasures of the Study" in China, and its Xuan paper (Jingxian), Xuan pen (Jingxian/Jingdezhen), Huimo (Jixi/Jingdezhen) and Xuanyan (Jingdezhen) are all top grades.