Mark-S wrote: ↑Mon Mar 09, 2020 2:44 pm
I just visited their website and the teapots are not overly expensive. With custom pot you mean that you select one of their styles and you tell them what clay you want them to use? I have seen that they also sell blue colored teapots. Can they be made without the use of additives? I always liked them, but did not want to poison myself.
You choose a shape, size, polished or rough surface, higher or lower fired, maybe can even choose the kiln type.
No, blue pot needs cobalt oxide to be added. Same for dark green. The problem comes with overdosing these additives, which makes them easier to leach, or when these colors are not achieved by simply adding these oxides, but other stuff too, combined with lower firing.
Adding certain oxides doesn't make something unhealthy, especially not, because the base clay is made of those same oxides. However it cannot be overdosed. Gu Jingzhou said a maximum of 1.5%-2% can be added. He too also made blue and green pots.
Adding coloring oxides to the clay existed since the ROC times. Where the practice came from jingdezhen.
What makes cheap pots dangerous is the combination of all the chemical stuff they add, and usually overdose, such as, overdosing BarCarb, and manganese oxide, while acid washing, and mixing with glass water, all in random clay from one part of china, which then is fired at a low temperature.
Personally I prefer completely natural clay, or clays mixed together.