Pastel, also known as "soft color", is a variety of overglaze porcelain. The so-called overglaze color refers to the color painting on the burned glaze of plain ware, which is baked in the kiln at a temperature of 600 ℃ to 900 ℃. Generally, the painting method of pastel porcelain is to draw the outline of the pattern on the high-temperature fired white porcelain, then use arsenic containing glass white as the base, and then apply the pigment on this layer of glass white, and gently wash the color according to the different needs of depth with a clean pen, so that the petals and human clothes have a sense of light and dark. Due to the opacification effect of arsenic, the glass white has the feeling of opacity. When it is combined with various colors, it will produce chalking effect. The red color will turn pink, the green color will turn light green, the yellow color will turn light yellow, and other colors will also turn into opaque light tones. The amount of arsenic can be controlled to obtain a series of different shades of color, giving people a sense of softness. Therefore, this overglaze color is called "Pastel". In terms of performance techniques, From flat filling to light and dark washing and dyeing; In style, its layout and strokes have the characteristics of traditional Chinese painting. The "glass white" used in pastel porcelain is an opaque white opacifier, which belongs to the compound of lead oxide, silicon and arsenic. By using its opacification, it can make the color painting appear thick and light concave and convex changes, increase the expressiveness of the color painting, make the picture pink and soft, and rich in the style of traditional Chinese painting. Therefore, it has won the reputation of "Pearl of Oriental Art".