Authenticating a porcelain sculpture without documentation requires a combination of expert observation, scientific analysis, and historical research. Here are the most effective methods:

1. Visual Inspection: Examine the sculpture for craftsmanship details like glaze consistency, brushwork, and mold marks. Authentic pieces often show subtle imperfections, while reproductions may appear overly uniform.

2. Material Analysis: Test the clay composition and glaze chemistry. Tools like X-ray fluorescence (XRF) can identify trace elements unique to specific regions or time periods.

3. Provenance Research: Trace the sculpture’s ownership history through oral accounts, auction records, or collector networks. Even without paperwork, anecdotal evidence can provide clues.

4. Style and Period Comparison: Compare the piece to documented works from the same artist or era. Look for stylistic hallmarks, such as signature motifs or firing techniques.

5. Expert Consultation: Seek opinions from appraisers, museum curators, or ceramic specialists who can spot subtle authenticity indicators.

By combining these approaches, collectors can confidently verify undocumented porcelain sculptures.