The standard for the quality of porcelain

‌I. Visual Characteristics‌

1. ‌Shape and Lines‌
   • Symmetrical and well-proportioned form with smooth, natural contours. For example, the proportions of a plum vase’s mouth, body, and base should harmonize[‌4].
   • Flat base with cleanly finished foot rings, ensuring stable placement and no burrs[‌8].
2. ‌Color and Luster‌
   • Glaze should be uniform and pure. New porcelain often appears overly glossy, while antique pieces exhibit a soft, inner luminescence[‌1]. For instance, underglaze blue (qinghua) should be vibrant, and Ru ware should display consistent celadon tones[‌4].
   • No visible “wave marks” under backlighting. High translucency indicates thorough vitrification (testable with a smartphone flashlight)[‌7].
3. ‌Decorative Patterns‌
   • Designs should be intact and crisp. Gold/silver detailing must adhere firmly without fading when wiped. Underglaze patterns are protected by a transparent coating, enhancing durability[^1][^2][‌4].
   • Inferior pieces often show blurred, broken lines, peeling patterns, or garish color combinations[^6][‌8].

‌II. Craftsmanship and Material‌

1. ‌Body Quality and Density‌
   • High-quality porcelain features fine, dense clay. Kaolin-fired bodies are pure white and sturdy. A crisp, bell-like sound when tapped indicates integrity; a dull tone suggests cracks or low density[^1][^4][‌7].
   • Hand-thrown bodies reflect artisan skill, while natural mineral glazes produce jade-like textures[‌5].
2. ‌Glaze Integrity‌
   • Surface should be smooth, free of pinholes, bubbles, or impurities. Poor-quality glaze feels coarse and chips easily[^1][‌8].
   • Body-glaze bonding must be tight. Antique pieces resist weak acid cleaning, while imitation glazes may peel or contain artificial adhesives[‌1].

‌III. Functionality and Safety‌

1. ‌Performance‌
   • Reinforced porcelain resists chipping, magnesia porcelain retains heat, and bone china is lightweight yet fragile—choose based on use[‌2].
   • Low water absorption: Droplets on high-quality porcelain remain beaded without seeping[‌6].
2. ‌Safety Standards‌
   • Prioritize in-glaze or underglaze techniques to avoid heavy metal risks from overglaze paints. Check lead/cadmium migration test reports[^2][‌8].
   • Avoid cheap online glazed tableware with low compliance rates. Opt for brands with “China Green Product Certification”[‌2].

‌IV. Authentication Methods‌

Use the ‌“Observe, Listen, Compare, Test”‌ approach:

• ‌Observe‌: Check glaze smoothness, symmetry, and base finishing.
• ‌Listen‌: A clear, resonant sound indicates full vitrification.
• ‌Compare‌: Ensure color consistency and component harmony in sets.
• ‌Test‌: Verify lid fit or specialized functions (e.g., a公平杯’s controlled pour)