In pharmaceutical manufacturing, identifying cosmetic defects in lyophilized (freeze-dried) products is a vital part of visual inspection to ensure product quality, regulatory compliance, and patient safety. These defects, while not always affecting product efficacy, may signal underlying issues in formulation, filling, lyophilization, or packaging processes. Commonly encountered cosmetic defects in lyophilized products include cake shrinkage, cake cracks, coring, blowouts, frosting, fogging, glass delamination, color change, reconstitution haze, and surface pitting. Additional cosmetic anomalies such as bubbles in the cake, uneven lyophilized surface, wet or collapsed cake, foreign fibers, scratches on the vial, label misalignment, and stopper misplacement are also critical visual indicators of quality deviation.Visual inspection kits and KNAPP test kits specifically designed for lyophilized vial inspection incorporate these defects to train inspectors and validate manual or automatic visual inspection (AVI) systems. These kits simulate real-world defect scenarios across multiple container formats—ampoules, vials, and cartridges—and are used for GMP-compliant training, USP <1790> qualification, and Annex 1 visual inspection readiness. The inclusion of a diverse range of cosmetic defect reference vials supports robust inspector qualification, reduces subjectivity in visual inspection, and enhances consistency across batch release operations. Manufacturers also rely on these standardized visual inspection challenge sets for routine requalification, quality audits, and AVI performance benchmarking