In the antique ceramics market, condition is the second major determinant of value after authenticity. Its effect, however, is not linear. Different categories and quality levels tolerate damage very differently.

Classification of Damage

Grade A: Severe Impact on Value (50-90% Discount)

  • Hairline crack: a crack running through the wall of the vessel, visible to the naked eye and detectable by touch
  • Rim or foot loss: obvious loss at the rim or foot ring, with a chip exceeding 5mm
  • Restoration: evidence that the object has undergone professional restoration, visible under raking light or UV examination
  • Large glaze loss: more than 5% of the object's total surface area

Grade B: Moderate Impact on Value (15-40% Discount)

  • Hairline crack (hidden crack): a fine crack that requires raking light or UV light to detect
  • Base chip: a knock on the inner side of the foot ring that does not affect the front-facing display
  • Kiln flaw: glaze bubbles, glaze contraction, kiln grit adherence, and similar flaws created during firing; these are normal manufacturing imperfections

Grade C: Minor Impact on Value (0-10% Discount)

  • Use wear: slight wear to the interior or foot consistent with historical use
  • Crackle: in certain categories, such as Ge ware and guan ware, crackle is a technical feature rather than a defect
  • Burial accretion: earthen deposits on excavated wares, which may serve as evidence of origin

Tolerance by Category

Famous Song Wares (Ru, Guan, and Ge)

Market tolerance is highest. Because genuine examples are extraordinarily rare, even pieces with hairline cracks or restoration can still achieve million-dollar results. Several celebrated Song wares in the Sir Percival David Collection have varying degrees of damage, yet their status is unaffected.

Key principle: damaged genuine piece >> perfect copy

Ming Blue-and-White

Condition expectations are moderately high. For standard types, such as a Xuande lotus dish, the price gap between an intact example and one with a hairline crack can be 3-5 times. For rare objects with important subjects, however, the market is more forgiving.

Qing Imperial Wares (Yongzheng and Qianlong Famille Rose)

Condition expectations are strictest. Surviving numbers of fine Qing wares are relatively large, and intact examples are sufficiently available that buyers do not need to compromise. The price gap between an intact example and one with a hairline crack can often exceed 10 times.

Export Porcelain

Condition expectations are relatively relaxed. As commercial wares made for export, their collecting value lies mainly in subject matter and size; minor damage has limited effect on price.

Practical Authentication Tools

  1. Strong flashlight (raking light): for detecting hidden cracks
  2. UV lamp: for identifying restored areas, which fluoresce abnormally
  3. Touch test: slowly slide a fingertip around the rim to feel for small chips

Market Debate Around Restoration

Professional restoration, or restorer's work, is viewed very differently across markets:

  • European and American markets: restoration is considered a negative factor and must be clearly disclosed; failure to disclose can constitute fraud
  • Asian markets: high-quality restoration that is "invisible" has sometimes been tolerated, but as professional authentication becomes more widespread, expectations of transparency are rising

Principle: always inspect under UV light before buying.