Chinese lacquer, a natural polymer with exceptional durability and cultural significance, has been widely used since the Warring States period. This review examines recent advances in lacquer identification techniques and their role in cultural heritage conservation. Drawing on five representative case studies—the B54 Japanese armor, Ba lacquerware from Lijiaba, a Qing Dynasty folding fan, Ryukyu lacquerware, and late Joseon objects—we show how integrated analytical approaches combining microscopy, spectroscopy, chromatography, and biochemical methods provide critical insights into composition, degradation, and conservation strategies. Key findings highlight (1) the effectiveness of multi-technique analysis in characterizing complex lacquer–metal interfaces and layered structures; (2) the recognition of regional and chronological variations in lacquer formulations, highlighting the need for standardized authentication protocols and shared databases; and (3) the promise of non-destructive technologies to reduce sampling and improve aging simulations. By critically synthesizing these case studies, the review highlights both methodological successes and persistent challenges, such as ethical constraints of sampling and limited understanding of long-term degradation. Ultimately, lacquer is positioned at the intersection of material science and cultural preservation, offering a transferable framework for global heritage protection. Future directions include hyperspectral imaging, bioinspired consolidants, and computational modeling to advance non-invasive diagnostics and sustainable conservation.

Polychrome paintings on wooden artifacts are vital elements of cultural heritage, where plant-derived binders play a crucial role in color formation and durability. This study aims to systematically compare the chemical, optical, and surface characteristics of two traditional natural adhesives—acacia gum (AG) and tragacanth gum (TG)—to better understand their influence on the preservation and reproduction of wood-supported polychrome coatings. Fourier-transform infrared spectroscopy (FTIR) confirmed their polysaccharide-rich structures, with distinct ester and glycosidic linkages, while rheological tests demonstrated that TG exhibited higher viscosity at 1–3% concentrations, whereas AG showed a sharper increase at 5%, reflecting different molecular architectures. Colorimetric analysis combined with two-way ANOVA revealed that gum type significantly influenced color development in blue and red coatings (p < 0.001), while yellow and green coatings remained largely unaffected. Gum concentration (1–5%) generally showed no significant effect on color. All coatings exhibited a matte appearance (<3 GU), with statistical analysis indicating that gloss was mainly determined by pigment particle distribution rather than adhesive type. Surface roughness increased notably with gum concentration (p < 0.001), demonstrating that binder content strongly affects coating microtexture. Overall, pigment type was the dominant factor for color, whereas gum concentration critically influenced surface morphology. These findings provide practical guidance for optimizing natural adhesives in the conservation of traditional polychrome artifacts.