Can air-dry clay be painted?
Yes, air-dry clay may be painted after the object has fully dried. Tempera paint may be used. But it may flake or run off and will definitely come off with moisture. Acrylic based paints are moisture-proof and will seal the clayto a certain degree but it is not the same as glazing done in a kiln. Air-dry clay is not the best choice for vases or vessels you want to hold water as moisture will gradually seep through the bottom. Only kiln fired clays vitrify making them suitable for vases and food service items.