These tea cups are handcrafted by Xiang Bingcheng (向炳成), one of the most famous masters of Jianshui Zitao ceramic art. The creation was inspired by the ancient wells of Jianshui, and the deep grooves symbolize the marks rubbed off on the stone platform of  the wells by the ropes, since the hundreds of ancient wells are a representative symbol of Jianshui's culture.
 
- About the author.
Master Xiang, born in 1968, is a senior artisan in Yunnan Province. He has been a lover of painting and calligraphy since childhood and has got structured learning in Chinese painting and oil painting. In 1991, he started his career in the Jianshui Porcelain Factory as a kiln worker and began to learn the art of pottery systematically, and finally has grown into a master and leader of Jianshui Zitao in his thirty years of continuous exploration. Bei Shan Tao Zhuang (贝山陶庄), as you can see in the third photo and in the video, is the studio of master Xiang. 
 
- About the calligraphy.
It is a quote from Kongzi Jiayu, a Confucian classic written in remote ancient times B.C.
“君子修道立德，不谓穷困而改节。”
“A noble man cultivates himself/herself with ethics, his/her moral integrity does not alter even in predicament.”
 
Junzi Bei means "noble man's cup". Junzi (noble man) is a Chinese philosophical term, especially in Confucianism. There is no gender implied in the characters and it can equally refer to men and women, with a preferred translation as "respectable person".
 
- About the ceramics.
These teacups are the most typical styles of Jianshui Zitao ceramic art, using the very particular technique "carving and filling". All figures and calligraphy are not just painting, instead, are carved on the cup and then filled the grooves with clay of different colors. Unglazed, polished surface.