Bone China by John Shirley

John Shirley is a ceramic artist from South Africa, who was selected as a member of the International Academy of Ceramics in 2010. Here is John in his own words. 

John with his translucent work in South Africa

In 2000 while studying for my BTech in Ceramic Design I decided that I wanted to work in a translucent body (up until this time I had always worked with porcelain) but I wanted to try something I had not worked in previously.

It was then that I chose bone china as the medium I wanted to explore. This has really been an exciting journey and bone china is the body I still work with today.

​The body is traditionally fluxed with bone ash and feldspar and stabilised with Kaolin. Fired to 1250C it produces a body of extreme whiteness and excellent translucency.

​As a ceramist living in South Africa where the choice of raw materials is more limited and the quality is less regulated than in many other countries, I was determined to make a translucent body with local materials. This is where my choice to work with bone china really paid off. What I discovered is that the bone ash in the body acts as a bleach on any traces of iron present in the kaolin in the body. As the local kaolins are far from the extremely white kaolins available overseas this proved to be a real bonus.

Antoinette Badenhorst discussed the translucency of the porcelain and bone china soluble salts with John during her visit in Bryanston, South Africa

​I started with the usual recipe of 50% bone ash, 25% Feldspar and 25% Kaolin which I made into a casting slip, as bone china is almost impossible to throw. Although my first results were not ideal they were very promising and I adjusted this first test. I tried many different kaolins. I changed from bone ash to tri-calcium phosphate which is synthetically produced. And within a few months arrived at a recipe that produced the results I was aiming for. With a few tweaks from time to time this is the recipe I still use today.

​The body has a high shrinkage and a tendency to warp in the firing and although I have tried several ways to stabilize the body in the firing with various setters, I now accept the gentle warping produced by the firing as a part of the process.
Choosing to work with bone china for my work is I feel something that has worked really well for me and the work I produce with this body is quite different to any work I would have produced using the porcelain body I was using before.

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Links:

• Demonstrations, tips and techniques at TeachinArt
• Click here for the video Antoinette interviews John Shirley
• John Shirley website www.johnshirleyceramics.com 
• Antoinette's blog about difference between various kinds of porcelain

Tags:
#SouthAfricanartist #bonechina #JohnShirley #translucentporcelain #IAC