Multanni mitti is a fine-grained clay from the Multan region of Pakistan. It's been used for centuries — mainly in skincare, as a face pack and body treatment. I started testing it in ceramics during the residency, initially because I wanted to use it and nobody seemed to have documented what it does at high temperatures.
The short answer is: it's earthenware by nature, which means its natural firing point is lower than stoneware. When you push it to Cone 9 or 10, the glazes melt and break differently over it. So far I've seen reds and maroons appearing in places the same glaze wouldn't produce over white stoneware — particularly with Crystal Emerald, where the copper carbonate is reacting in ways I'm still tracking.
I use it as a slip decoration rather than a throwable clay on its own — a stripe running along the waist of the pot. Small pieces of Pakistan and Britain, linked together permanently in the kiln. As they already are through history.