As one of the important carriers of Tibetan ethnic minority culture inheritance on the Qinghai–Tibet Plateau, the basic properties and fiber morphology of grass paper from Stellera chamaejasme have a significant impact on its paper quality. The basic properties of grass paper from Stellera chamaejasme from six different production areas on the Qinghai–Tibet Plateau were systematically tested and analyzed according to relevant national standards, and the fiber morphology characteristics were experimentally observed. The results showed that the grammage, thickness, density, bulk, brightness, gloss, folding resistance, and tensile strength performance indicators of grass paper from Stellera chamaejasme on the Qinghai–Tibet Plateau were generally good; the basic properties of grass paper from Stellera chamaejasme in different origins vary to some extent; and the fibers of grass paper from Stellera chamaejasme are mostly yellow in color, with slender fibers and small, uneven widths. The ends of the fibers are sharp, and the fibers are arranged in a staggered manner. There is a phenomenon of fiber aggregation, showing a clear flat band structure with a clear mesh structure. The surface has many rough horizontal knots, visible cell cavities, mixed cells, and obvious longitudinal wavy folds. Therefore, the basic performance of grass paper from Stellera chamaejasme is excellent, which is consistent with the historical description of the excellent quality of Tibetan paper, and is closely related to its fiber morphology characteristics.

As a representative intangible cultural heritage of Tibet, China, Nyemo Xuelai Tibetan paper has maintained its millennium-old inheritance, relying on its unique surface properties and aging resistance. However, at present, there remains a research gap regarding the surface characteristics of Nimu Xuela Tibetan paper and their correlation with aging mechanisms. To reveal their intrinsic mechanisms and provide scientific protection schemes, this study systematically analyzed the surface microstructure, chemical composition, pH variation, and aging resistance of 7 groups of Xuelai Tibetan paper samples using SEM-EDS, ATR-FTIR, pH testing, and dry-heat aging experiments (105 °C, 144 h). Combined with traditional crafts, the formation mechanism of properties was clarified, and multi-dimensional protection strategies were proposed. The results show that aging time exerted a highly significant effect on the D65 brightness, pH value, and tensile index of Xuelai Tibetan paper (p < 0.001). The fibers of Xuelai Tibetan paper are flat and ribbon-like, with an aspect ratio of 50–80, forming a tightly intertwined network structure. The core chemical component is cellulose with a relatively low lignin content, and the elemental composition is dominated by carbon and oxygen. Some samples contain calcium-based substances (0%–1.79%) derived from salt lake alkali. After aging, the D65 blue light diffuse reflectance factor (abbreviated as D65 brightness) retention rate of the samples ranges from 84.81% to 92.21%, and the tensile strength retention rate ranges from 30.78% to 90.00%. Calcium-based substances can inhibit the hydrolysis of cellulose glycosidic bonds through a weak alkaline buffering effect, improving aging-resistance stability. The excellent performance of Tibetan paper originates from the synergistic effect of traditional crafts: Stellera chamaejasme as raw material provides the material basis of high cellulose and long fibers; alkaline cooking removes lignin and retains the buffering components; manual beating optimizes the fiber’s interweaving structure; and natural air-drying ensures surface uniformity. Based on this, a multi-dimensional strategy of preventive protection and living inheritance is proposed: cultural relic protection focuses on pH stabilization, controlled storage, and non-destructive cleaning, and craft inheritance achieves sustainable development through raw material standardization, process refinement, and digital training. This study establishes the craft–characteristic–performance correlation mechanism of Xuelai Tibetan paper, verifying the statistical significance of aging-induced property changes and providing a scientific basis for the protection and inheritance of traditional handmade paper.

Qiangduo Tibetan paper is a typical intangible cultural heritage in the Shangri-La region of Yunnan, China, mainly handmade from two local fibrous plants, Stellera chamaejasme and Wikstroemia canescens. This study focuses on the correlations among its surface properties, water absorption and dry heat durability, which are critical for heritage conservation. Four paper samples (Z1–Z4) were investigated via micromorphology, physicochemical property testing and dry heat aging (105 °C, 216 h). The results show that the two raw materials lead to distinct fiber and pore structures: Stellera chamaejasme paper has coarser fibers and loose pores, while Wikstroemia canescens paper has finer and denser fibers. All samples present a near-neutral to weakly alkaline pH (6.87–7.56) and favorable water absorption, jointly regulated by fiber structure and alkaline wood ash fillers. After dry heat aging, all samples undergo whiteness loss, tensile index decay and slight acidification, with extremely significant changes (p < 0.001). Notably, Stellera chamaejasme paper exhibits much higher aging resistance, with whiteness and tensile index retention reaching 77.97%–93.07% and 71.46%–74.77% respectively, far superior to Wikstroemia canescens paper. The mechanism lies in the high flavonoid content and low lignin level in Stellera chamaejasme fibers, which enhance antioxidant stability and reduce yellowing, whereas the opposite composition accelerates degradation in Wikstroemia canescens paper. This study provides a scientific basis for the conservation, inheritance and targeted application of Qiangduo Tibetan paper, supports the sustainable protection of handmade paper cultural relics, and enriches the application of surface science in cultural heritage conservation.