Seasoned porcelain collectors employ multiple methods to differentiate between limited editions and unique pieces. Limited edition sculptures typically bear numbered markings (e.g., "15/100") and come with certificates of authenticity documenting the production quantity. These works often show minor variations in glaze or form within the edition.

Truly one-of-a-kind creations display distinctive characteristics: unique glazing patterns impossible to replicate, experimental techniques, or the artist's handwritten signature rather than stamped markings. Auction houses and galleries verify uniqueness through three key factors: absence of edition numbers, documentation of singular creation, and technical analysis revealing unrepeatable firing effects.

Experts examine clay composition - limited editions use standardized clay batches while unique pieces may incorporate custom blends. Surface textures also differ; mass-produced molds create uniform details whereas hand-built sculptures show individual tool marks. Provenance research proves crucial, as authentic unique pieces always have exhibition histories or documentation of their creation process.

Advanced collectors often use ultraviolet light to detect restoration work that might indicate a prototype rather than true limited edition. The most valuable one-of-a-kind pieces typically come from important artist periods and demonstrate technical innovations not seen in their editioned works.