Where does Pear Skin Zhuni come from? How is this bumpy texture created?

Sometimes marketed as being an exotic variety of zhuni clay, or old storage “lao” zhuni clay, pear skin zhuni is produced through a very old technique that is still practiced in Yixing today, called 调砂 Tiaosha.

Where does it come from and what exactly is it? Hongni is one of the most enigmatic clays in Yixing. 

One of the first things that you will read about Yixing Teapots is that they “season” with use.