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.

Inclusion Criteria:

1. Chinese female, aged between 20 and 70 years (inclusive) at the time of signing consent.
2. Willing and able to provide written informed consent.
3. Fitzpatrick Skin Phototype II or III.
4. Willing to comply with all study procedures, including removal of facial makeup and avoidance of intensive skincare (e.g., retinoids, strong acids) on the test areas for 3 days prior to the visit as per instructions.

Exclusion Criteria:

1. Pregnant, planning pregnancy, or breastfeeding (as hormonal changes significantly affect skin properties).
2. Presence of temporary tanning, sunburn, or significant erythema on the face or measurement areas.
3. Presence of facial piercings, tattoos, too much fluff or significant scarring that would interfere with imaging or measurements in the areas of interest.
4. History of any aesthetic or surgical procedure on the face (e.g., laser therapy, chemical peels, injectable fillers, botulinum toxin, plastic surgery) within the past 12 months.
5. Current diagnosis or visible signs of a skin disease (e.g., psoriasis, eczema, active acne, rosacea) or a systemic disease known to affect the skin (e.g., diabetes, lupus) on the face or measurement areas.
6. Use of systemic medications known to affect skin physiology (e.g., oral retinoids, immunosuppressants, long-term corticosteroids) within the past 3 months, or for a cumulative duration of ≥6 months within the past 2 years.
7. Participation in another clinical study on the face or arms within the past 1 month.

Approximately 100 healthy Chinese female Subjects, evenly distributed across age groups (20-29, 30-39, 40-49, 50-59, 60-70 years).