Types of identifying marks on antique china include incised marks, impressed marks, underglaze marks and overglaze marks. Other common types of identifying marks on antique china include painted marks and printed marks, such as manufacturer stamps.
An incised mark is a type of identifying mark on antique china that is handcrafted when the first basic china model is finished. Incised marks are created before the first firing of the china piece when the clay is still soft. Impressed marks are also created this way, but differ from incised marks because impressed marks are stamped into the clay rather than crafted by hand.
Underglaze marks are painted or printed marks on antique china that are created after the first firing but before the glaze is applied. Underglaze marks are painted using metal oxides that are resistant to high kiln temperatures. Cobalt is often used to create incised marks and displays a blue underglaze marking.
Overglaze marks are painted or printed marks created after the glaze is applied, but before the final firing. Overglaze markings also use metal oxides, most commonly iron oxide, which displays a red color, and copper oxide, which displays a green color. Overglaze marks may be created using gold, but only if the final firing temperature stays below 400 degrees Celsius.