Yunomi is the Japanese word for “upright handleless teacup”. I make a lot of these kinds of forms and use them as wine glasses, water tumbers and whisky sippers.
These are glazed using a very old ash recipe called “Leach 442”. The 442 refers to the quantity of ingredients in the glaze – 40% Ash, 40% Feldspar (a ground up rock) and 20% powdered clay. When combined this mixture will melt at around 1200c and produce this opalescent glaze. I fired them in my gas kiln and fellow potters can view the recipe on glazy.org.
Below you can see the same glaze on a different clay. It makes a huge difference!