During the Republic of China, it began to imitate the three colors of the Tang Dynasty. Since the 1980s, the imitation of Tang Tri-colors in Luoyang has been mainly concentrated in the area from Chaoyang in Mengjin County to Nanshishan Village in Mangshan Mountain. The three colors produced here are mainly handicrafts and some imitations. So how to distinguish the authentic Tang tricolor from the imitation Tang tricolor? This can be started from four aspects: modeling, glaze color, carcass and technology. (1) modeling. Tri-colored Tang Dynasty was created by craftsmen in a specific historical period, which was closely related to the social customs, living environment, aesthetic consciousness, production materials and technological level at that time. Therefore, both people and animals can show vivid expressions and rich flavor of life. From the unearthed tri-color sculptures of the Tang Dynasty, it can be seen that the level of sculptures by craftsmen in the Tang Dynasty is very high, with exquisite skills, harmonious proportion of figures and animals and vivid images. People's faces, facial features, expressions, postures and gestures change, and all kinds of animals are still or moving, and their shapes are natural and vivid. The production of imitations is based on the original, the second is based on pictures, the third is the innovation of prototypes, and the fourth is fabrication. Although the producer has made great efforts in modeling, some of them are similar to the original, but due to the lack of basic skills of sculptors and the different living environment between the producer and craftsmen in the Tang Dynasty, the products produced can only be similar in shape but not in spirit, often with stiff modeling and lack of change. For example, the proportion of figurines is often uncoordinated, the face is dull, the lines are stiff, and some lines are too regular. In the Tang Dynasty, the bottom foot of tricolor round vessels was generally in the shape of "flying edge", and a knife was repaired outside the edge, which was more common in bowls, plates, bottles, pots and other utensils, but imitations often lacked this technology. (2) glaze color. Tang Sancai was buried underground for more than 1000 years. Due to the erosion of soil environment and chemical substances such as acid and alkali in the soil, the original bright luster becomes soft and shiny. The glaze is even and fine, and the four sides of the glaze are slightly upturned. Carefully observe the corroded silver mud in the cracks of the fragments with a magnifying glass, which is similar to the phenomenon of lead flooding in the blue glazed pottery pots of Han Dynasty. Directly observed with naked eyes, the surface layer of glaze is seen from the side, forming a thin layer like a fly's wing, and the lines between pieces are like protruding lines, which is the "patina" of Tang Sancai. In order to remove the dazzling luster of glaze, imitations often use hydrofluoric acid to remove the light and then use alkali to neutralize it, so they look rough. In recent years, producers have also studied the firing method of small pieces of glaze, but the pieces are hard, some are too thin, and some lines are messy. Individual lines are often too long when opening the film, and there are no flying wings on the glaze. Although some have also made a layer of silver or five-color iridescence, it is as shallow and unstable as a mist floating on the glaze. (3) the carcass. Tang Sancai unearthed in Luoyang contains trace amounts of iron. Due to the different firing temperature and atmosphere in the furnace, the color of the fired carcass is white, light pink or light yellow, and the tire quality is not very fine. Fetal mass contains tiny particles like chronotropic and other mineral impurities. Judging from the firmness of the carcass, some are hard because of high firing temperature; Some of them have low sintering temperature, low hardness, loose carcass and easy peeling of glaze layer. One way to make imitations is to use pure kaolin, that is, the matrix material of modern tricolor handicrafts, which contains no special ingredients. After firing, the carcass is white and delicate, relatively hard, with few impurities, loud knocking sound and heavy hand feeling, which is very different from the tri-color handicrafts in Tang Dynasty. Another material is kaolin. The processing technology of tire material is similar to that of ancient times. Manufacturers strive to add a small amount of quartz powder and other substances to tire materials. After careful production, the hardness, tire color and density of sintered tires are close to those of the Tang Dynasty, so it is difficult to distinguish them. (4) technology. Tang Sancai is generally composed of sculpture, mold turnover, blank pressing, and adhesive assembly. At the same time, the method of wheel making and kneading was adopted, leaving these technological traces on the figurines and utensils. People and animals are mostly molded in sections, pressed by hand and bonded with clay. Judging from the unearthed objects, these traces are very obvious. If we carefully observe the treads inside these three-color corpses, many of them have the fingerprints of craftsmen in the Tang Dynasty. Flat circular tricolor objects, such as flat pots, basically have butt joints and knife marks on their sides. Such as bowls, cans, bottles, sprinklers, plates, bowls, etc. They are all made by wheel method, and the small chords left in the production process are clearly visible. Some imitations adopt grouting technology, but there is no kneading, wheel making, mold closing and mud sticking technology on the carcass of the object. Its manufacturing method is very different from the real one, and the finished product feels lighter. Some round objects are placed on the turntable after grouting or molding, and a series of wheel marks are drawn by the rotation of the turntable, but the chords look unnatural. Some of them are made by a molding process similar to that of the Tang Dynasty, but after the combination, no matter the figures, animals or utensils, they all look clumsy, with uncoordinated proportions and stiff lines. Others are too elaborate, gild the lily, and people can't feel the charm of the three colors in the Tang Dynasty. Under normal circumstances, the skin of Tang Sancai figurines that is not covered by clothes is not glazed, such as the face, neck and hands of the figures, which are generally painted. Hair, eyebrows, eyes, beard, towel and hat are black, and lips and cheeks are scarlet. The facial features and beards of the characters are described in detail. After thousands of years, the colors of these paintings are getting lighter and lighter, and they have penetrated into the carcass. The imitation painting is bright and clear, looks floating, the sketch lines are not clean and neat, and the characters' expressions are dull. The brushwork used to describe is often not in place and is different from the original.