This is a single-center, non-interventional, observational, cross-sectional clinical study designed to quantitatively and qualitatively characterize skin properties in a cohort of 100 Chinese female Subjects aged 20 to 70 years. The study involves no product application and poses minimal risk to participants. The primary objectives are to establish a comprehensive skin aging profile database, characterize skin color, aging signs, and biomechanical properties, and create a histomorphometric database for the development and validation of ordinal photographic scales for aging research. Data will be collected through questionnaires, clinical assessments (including LC-OCT imaging), standardized photography, and non-invasive biophysical measurements. All procedures will be conducted in accordance with the ethical principles originating from the Declaration of Helsinki, the International Council for Harmonisation Good Clinical Practice (ICH-GCP) guidelines, and the relevant laws and regulations of China (including the \*Measures for the Ethical Review of Biomedical Research Involving Human Subjects\*). All data will be anonymized and stored securely.