Lipini, the Pear Skin Clay

1 ½ tons of rock sat in the yard behind Lin Hanpeng’s studio in Yixing while men smashed it into pieces with hammers. This rock, after crushing, separating and processing, yielded mostly tianqingni, but also some lipini. While tianqingni is seen as one of the most precious varieties of zini (purple clay), lipini is rarer still, appearing only in thin layers between tianqingni deposits. As we mentioned in our previous article, lipini is a kind of lüni, a soft and crumbly zisha ore containing relatively little iron oxide and appearing pale yellow after firing.
 
The tianqingni clay will sit in storage ageing for another 6 months or more before it is ready to be used. However, Lipini doesn’t require the same resting period. As I write, a small set of lipini teapots has just emerged from the kiln.
 
Having fired a lipini teapot successfully, Lin Hanpeng turned to write an article to detail the steps taken from raw ore to finished teapot. The following is our English translation of Lin Hanpeng's article with photos courtesy of Mr. Lin.

Jade Pear: The story of its birth
 by Lin Hanpeng
​
This article records the birth of a lipini pear teapot from start to finish; from original ore to finished product.
 
Original ore 原矿
 In the book 《阳羡茗壶系》“Yanxian Famous Teapot Series” written during the Ming Dynasty, the author 周高起 Zhou Gaoqi writes, “天青泥，出蠡蜀，陶之乃变黯肝色。又其夹脂有梨皮泥，陶现冻梨色。” “Tianqingni from Lishu [part of Huanglongshan]; after it is fired, the colour resembles dark liver. The “layer of fat” on the tianqingni ore is Lipini. After it is fired, [Lipini] is a cold pear colour.” Tianqingni is a very premium, very rare kind of zisha. Lipini is only a thin layer attached to tianqingni ore, making it even more precious. As the photo below shows, tianqingni and lipini are formed together. Lipini is found as a thin layer between tianqingni and the higher layers of ore.

Our studio has collected a very small amount of tianqingni original ore; this year we plan to take original ore and process it to use for teapots. [After the ore had been broken up into smaller pieces and] When we left the original ore to weather outside, I handpicked the pieces of ore that only contain lipini. Within 1.5 tons of original ore, I only managed to pick out 10kg of pure lipini original ore.

练泥 Clay Processing 
The next step is to turn lipini original ore into lipini clay that can be used to make a teapot. Zisha ore will break up when placed in water. I place them into water and let them soak and break up by themselves. After two weeks, whatever has broken up into clay can be used, whatever has not cannot be used and will be discarded [The material that doesn’t break up is not pure zisha and cannot be processed into clay]. Since I picked only the small pieces without any visible signs of other material, this time the ore broke up into the water without us needing to discard much material. After it breaks down into small pieces, we let the material air dry in the yard. Only completely dry zisha can be ground in the stone grinder. 

​After it has been dried, the zisha will need to be ground further into a powder. Although the zisha already looks powdery, you can see from the before and after photos below, that grinding it further does remove any visible chunks and turns the zisha into a soft fine powder.

​After it has been ground into powder, the next step is to add water to mix the zisha powder into clay. Usually, after grinding the clay into powder, it will need to be sieved so that the size of the grains of the powder are even, however, the amount of lipini powder is too little – only 10kg – and besides, I prefer a grainy texture for these teapots. So, I didn’t sieve the powder, I [skipped this step and] directly added water. The clay is stirred in the water using bare hands. The reason for doing so, is you can feel the texture of the clay as you stir it, and you can tell when the clay reaches the right texture, whether you need to add more water or not. Too much or too little water can ruin the clay and make it harder to process and age, so that it will be suitable to shape into teapots. After mixing the clay, I put it into a bag, close it, and let it sit for 10 days so the clay can fully absorb the water. I then use a vacuum to remove the air from the bags. Removing air is a crucial step. Any air left in the clay will cause the clay to break during firing in the kiln.

制作及烧成 Making and Firing 
Lipini is very easy to shape, after 2 weeks of vacuum-sealed storage, it can be shaped into teapots and fired. I had already made up my mind a long time ago to use this clay to make pear shape teapots. Pear skin, pear shape, they match each other. Besides, the pear shape is a very classic style of teapot for gong fu cha. It is elegant and practical. I think many people like this shape.

The last step is firing. The firing range for lipini is quite wide. Anything within the range of 1176C-1200C is possible. Before making the teapots we tested the clay by firing it at 1180C, 1184C, and 1190C. I found that 1184C is perfect, not under or overdone. Below are the photos of the teapot fired at 1184C. Looking at the color and texture, the clay resembles real pear skin to my eyes. It’s quite magical. 古人诚不欺我也 The ancients were honest and didn’t cheat me. I didn’t sieve the clay, so the grains make up 60% of the body of the teapot [Lin Hanpeng is referring to the large grains in the clay. Processed clay is said to consist of “meat and bones” 肉和骨,  the large grains are bones, and the fine particles are meat. The grain size in these pots is quite large, from 30-40目]. Grainier clay is more difficult to work with, however the texture has more depth and the clay will be more porous and breathable. The clay balances the grainy texture with a soft feel making the clay very sophisticated.