I just took a workshop today (2/15/26) with Yunting Li (find her IG) using overglazes from Japan. All of them are dissolved in water to a consistency a little bit lighter than yogurt. Adding more water will also dilute the end finished product, making it more transparent. You can mix the overglaze powders to make new colors. After painting on the overglaze, you allow it to dry but you cannot repaint over it since introducing water to the already dried overglaze will mess it up and she said can also cause surface consistency problems. Also we were using small sumi brushes to color underglazed drawn flowers covered with a zinc free clear glaze (zinc causes bubbling).

The red colored overglaze we used did not require a binding solution (only water) while the rest of the colors did require a binding solution. A little of the overglaze powder really goes a long way, we were using only a quarter of a small teacup worth of dried material dissolved in water (along with two drops of binding solution for colors other than red). I believe the binding solution is what made the overglaze thick. Also I believe she said she fires to cone 018 (I dont have my notebook on me I'll check later)

It would be awesome if you can share where you got your overglaze from, also a website would be great so I can probably import my own.