Ancient Chinese porcelain craftsmanship boasts a long-standing history, evolving from primitive pottery into mature celadon, white porcelain, and blue-and-white porcelain, embodying the wisdom of countless artisans. Below are the key steps and technical aspects of ancient porcelain production:
1. Raw Material Preparation: Porcelain Clay and Glaze – Selection of Porcelain Clay: • Kaolin (widely used after the Ming Dynasty): Sourced from Gaoling Village in Jingdezhen, Jiangxi, known for its pure and fine texture, resulting in high whiteness and excellent transparency after firing, serving as the core material for porcelain bodies. • Porcelain Stone: Contains minerals such as quartz and feldspar. When mixed with kaolin, it reduces body shrinkage and enhances hardness. • Other Clays: Specific clays were required for glazes like the “Plum Green” glaze used in Longquan kilns. – Glaze Formulation: • Natural Mineral Grinding: Celadon glazes required iron-containing minerals (e.g., ochre, malachite), while cobalt oxide was used for blue-and-white porcelain, and copper oxide for copper-red glazes.Purification and Refinement: Minerals are crushed, washed, and sedimented to remove impurities.
Forming Techniques: 1. Hand Shaping • Throwing: Clay is rotated on a potter’s wheel and shaped into bowls, plates, or vases (Song Dynasty Longquan kiln artisans could create 1-meter-wide jars). • Trimming: A blade refines the edges to ensure uniform thickness. • Pinching and Carving: Used for complex shapes like figurines or animals (e.g., Tang Sancai tomb figures). 2. Mold Printing • Clay is pressed into patterned molds for mass production (e.g., Ming/Qing imperial kilns’ coiled dragon motif plates). Decoration Methods: 1. Body Decoration • Carving/Incising: Sharp tools etch lines on unfired clay (e.g., Song Dynasty Yaozhou kiln carved plum vases). • Stamping: Molds imprint patterns (e.g., Ding kiln white porcelain lotus plates). • Appliqué/Openwork: Clay is stacked for 3D designs or pierced (e.g., Yuan Dynasty blue-white lotus petal jars). 2. Underglaze Painting • Blue-and-White: Cobalt oxide pigment is painted on bisque and coated with transparent glaze (first high-temperature underglaze blue from Jingdezhen, Yuan Dynasty). • Underglaze Red: Copper oxide creates red hues after firing (peaked in Ming Xuande era). 3. Overglaze Painting • Low-temperature pigments applied post-firing (e.g., Qing Dynasty famille rose and enamel wares). Glazing: • Dipping: Immersing pieces in glaze for simple shapes (e.g., bowls, dishes). • Blowing: Glaze is blown through bamboo tubes onto complex surfaces (e.g., bottle necks, feet). • Pouring: Glaze is poured over large items in molds. Firing Processes: 1. Single Firing (Bisque Firing) • Low-temperature: Primitive pottery (e.g., Yangshao culture painted pottery, ~800°C). • High-temperature: Hard porcelain requires 1200°C+ (e.g., Song Ru kiln ~1300°C, Longquan ~1280°C). 2. Double Firing (Glaze Firing) • Bisque is fired first, then glazed and low-fired (e.g., Ming/Qing enamel colors, ~800°C). 3. Kiln Types • Mantou Kiln: Circular, enclosed; ideal for small items (widely used in Tang Dynasty). • Dragon Kiln: Slope-built along hillsides; accommodates large pieces (common in Song official kilns). • Hulou Kiln: Jingdezhen innovation combining Mantou and Dragon kiln advantages for precise temperature control. Technological Breakthroughs & Notable Kilns: • Tang Dynasty: Yue Kiln’s ‘Mise’ porcelain controlled iron content and temperature for celadon-yellow glaze, exclusive to royalty. • Song Dynasty: Five Great Kilns – Ru Kiln: Sky-blue glaze (containing trace Ru clay) with ice-crackle patterns.Official Kiln: Pale celadon glaze with low-iron clay body presenting a beige tone.
Ge Kiln: Combines golden thread and iron wire patterns with crackled glaze effects. Jun Kiln: Flambé glazes blending red and purple hues through kiln transformation. Ding Kiln: White porcelain with carved designs, fired upside-down leaving unglazed rims. Yuan Dynasty: Blue-and-white porcelain and underglaze red achieved using imported cobalt pigment (high iron content) for intense coloration, successfully fired alongside copper-red glazes. Ming and Qing Dynasties: Doucai (contrasting colors) technique featuring underglaze blue outlines overpainted with enamels, exemplified by Chenghua chicken cups; and Falan cai (enamel colors) incorporating Western techniques reaching its zenith during Qianlong period. Cultural Significance: Maritime Silk Road exports during Song Dynasty made porcelain synonymous with China. Jingdezhen maintains of traditional craftsmanship (e.g. 72-step eggshell porcelain production), elevating Chinese ceramics from utilitarian ware to artistic treasure through generational innovation.