Sunday, 11 January 2009

Why Bone China?

Ever since my first experimentation with porcelain bodies, my quest has been the pursuit of whiteness and translucency. Unfortunately in South Africa, where I work, the local kaolins are not very pure. The idea of importing a kaolin did not appeal to me as I have always been determined to make my bodies using local materials. After achieving limited success with porcelain tests, cream rather than white and little, if any, translucency, I experimented with a few bone china recipes.
From the first tests the results were incredible. Whiteness that I had only imagined. It transpires that the bone ash, which makes up a large part of the body, has a bleaching effect on any iron traces in the kaolin, producing a body of extreme whiteness and increased translucency. Recently I have started adding bentonite to the body to increase green-strength. Bentonite, which itself contains small quantities of iron usually making porcelain tests creamier, rendered the bone china, if anything, whiter than it was before the addition.

1 comment:

Chris Callier Ceramics said...

So perfect... such a fresh, nice colour balance... almost aquarel!!
Thanks for shering it...