The specific ways to differentiate between overglaze and underglaze tableware are as follows:
a).Observe the surface texture and colour of the tableware: underglaze tableware is usually darker in colour and has a smooth surface; overglaze tableware is lighter in colour and may have a slightly rough surface.
b).Scratch test: scratch the surface of tableware with metal ware or sandpaper with high hardness, the depth and brightness of the colour on the surface of the underglaze tableware will be reduced, leaving obvious traces; the surface of the overglaze tableware will not leave traces.
c).Check the production process and characteristics: underglaze colour is in the tableware molding, the pigment and glaze mixed with the surface of the tableware, and then high temperature firing, the colour layer and the surface of the tableware tightly combined; overglaze colour is in the tableware surface after the application of colours and glazes, and then firing, the colour layer covered in the surface of the tableware.
d).Observe the glaze reflectivity: underglaze colour glaze reflective area is small, reflective effect is weak; glaze colour glaze reflective area is larger, reflective effect is stronger.
e).Check whether the body is even: the body of underglaze colours is usually more even, and the decorations are usually painted on the whole body and then glazed and fired; the production process of overglaze colours is to print the colourful patterns on the made body and then glazed and fired.
