Detecting overpainting or retouching in antique porcelain sculptures requires a combination of technical expertise and advanced tools. Here are the most effective methods to identify alterations:

1. UV Light Examination: Ultraviolet light reveals inconsistencies in paint layers. Original glazes typically fluoresce uniformly, while retouched areas may appear darker or uneven.

2. Microscopic Analysis: High-powered microscopes help identify brushstroke variations, modern pigments, or layered overpainting that deviate from the original work.

3. X-ray Fluorescence (XRF): This non-invasive technique detects chemical composition differences between original and retouched sections, exposing modern materials.

4. Cross-Sectional Study: Tiny samples analyzed under microscopy can reveal paint layer sequences, exposing added layers not present in authentic pieces.

5. Historical Comparison: Matching the piece’s style, glaze, and pigments with verified period examples helps spot anomalies.

By combining these techniques, collectors and experts can accurately assess porcelain sculptures, preserving their historical integrity and market value. Always consult a professional conservator for definitive authentication.