The appearance quality of porcelain mainly refers to the gloss, whiteness and chromatic aberration of the product surface, as well as the specification, size, matching, flower surface and other allowed common defects. 

(1) the whiteness of white porcelain (recommended indicators), glaze glossiness (except fog glaze) and the color difference of the complete set of products should meet the requirements, as shown in the table.Whiteness, glossiness, chromatic aberration index project grade excellent grade a qualified product whiteness is greater than or equal to 70.0 is greater than or equal to 60.0 is greater than or equal to 55.0 glossiness is greater than or equal to 85.0 is greater than or equal to 80.0 color difference is less than or equal to 1.0 is less than or equal to 2.0 is less than or equal to 3.0

(2) according to the national technical standards, the products are divided into three levels of first-class, first-class and qualified products, each of which has a different range of defects allowed. 

(3) product specification error A.The allowable error of diameter equal to or greater than 60mm is plus or minus 1.5%, and the allowable error of diameter less than 60mm is plus or minus 2.0%.B. Height error: + / - 3.0%.C. Quality error: + / - 6.0%. 

(4) the cover is basically identical with the mouth.Pot of class at 70 °, the lid is not allowed to fall off.When the lid moves to one side, the distance between the lid and the spout shall not exceed 3mm.The mouth of the spout shall not be lower than 3mm of the spout. 

(5) complete sets of products are required to be matched without errors, and the color requirements of flower surface are basically the same. 

(6) the glaze, flower surface, mouth, bottom (along) of the superior product is basically smooth, should be smooth on the plane.The glaze surface, flower surface, mouth, bottom (along) of grade a product, qualified product is basic and smooth, put on plane basic and smooth. 

(7) the bottom mark (referring to the pattern and text of the trademark) shall be correct and clear without obvious skew or eccentricity. 

(8) the product appearance quality standard is divided into 24 kinds of defects, such as deformation, blister, black spot, shrinkage glaze, etc.Be sure to check the number and take your seat when dealing with it. 

(9) distinguish the types and types of products (i.e., large, medium, small, bowl, plate, cup, pot). 

(10) the product is not allowed to cheat the glaze (lack of glaze), bump (along the wool), crack (billet burst) and leakage defects.Because, the product that has these blemish cannot use.(11) there is a difference between visible and non-visible products.For example, the inner surface of a bowl or cup, the outer surface of a pot or lid, and the upturned surface of a plate are called visible faces, while the rest are called non-visible faces.Visible and non-visible surface distinction, mainly because some defects in the non-visible face, can be allowed in the standard provisions of the range of defects will be increased.(12) product appearance quality grading, must meet the following requirements: 1.(2) grade a products each product shall not exceed 4 kinds of defects.(3) qualified products each product shall not exceed 6 defects.